After trying to load a project, files does load into the IDE, in the left down area some sort of progress bars that stays animated forever but files are not loaded.
app-lab runs locally on the uno-q board (via ssh -X)
First I try to run app-lab via network/ssh, but these progress stays animated, but I find this in the logs:
Nov 09 12:25:43 uno-q-first sshd-session[1878]: error: no more sessions
Nov 09 12:25:43 uno-q-first sshd-session[1878]: error: no more sessions
Nov 09 12:25:43 uno-q-first sshd-session[1878]: error: no more sessions
Nov 09 12:25:43 uno-q-first sshd-session[1878]: error: no more sessions
Nov 09 12:25:43 uno-q-first sshd-session[1878]: error: no more sessions
Nov 09 12:25:43 uno-q-first sshd-session[1878]: error: no more sessions
After raising MaxSessions to 50 in sshd_config the source files does not load either, and these messages does not appear again .
Hi @cassuu. I'm going to ask you to provide some additional information that might help us to identify the problem.
This procedure is not intended to solve the problem. The purpose is to gather more information.
Please do this:
Click the "Applications" button at the top left corner of the UNO Q's Linux desktop.
A menu will open.
Select "Terminal Emulator" from the menu.
A "Terminal" window will open.
Type the following command at the command line prompt in the "Terminal" window:
tree -a ~/ArduinoApps/copy-3-of-home-climate-monitoring-and-storage/
Press the Enter key.
You should now see a text representation of the file structure of your "Copy 3 of Home climate monitoring and storage" app printed in the terminal.
Select the output from the command.
Copy the selected output.
Open a reply here on this forum topic by clicking the "Reply" button.
Click the <CODE/> icon on the post composer toolbar.
This will add the forum's code block markup (```) to your reply to make sure the error messages are correctly formatted.
I seem to have a similar issue. I can start and stop one of my apps using ssh and arduino-app-cli but App Lab never manages to show the files and I cannot start or stop it from App Lab. None of my other user apps have this issue. One difference I used git on the command line to make the project folder a git repository so there is a .git hidden directory in there. I do not think this cause the issue as I do not think the problem started at that time. This app was my default app for a time. Later I made a different app the default app. I wonder if that has anything to do with it.
It will start and show your files as soon as you delete .cache and data folders. But then your influx container will not start, so it so-so solution.
Obviously, AppLab should ignore big subfolders with 30Mb of data
In general, this AppLab bug is very easy to reproduce - copy climate example (you can't run it without copying anymore because of Modulino library). Change modulino from 5.0 to 6.1. Start it. All good so far. Data are collecting, web server is nice. Now close your AppLab and try to open your copy again - voila - it will not open. I did it 5 times already....
I believe this is the cause. I performed an investigation and found the fault reported by @cassuu occurs when there is any empty folder under the App. Unfortunately Git commands may produce empty folders, putting the App into a broken state.
The Arduino App Lab developers have already fixed the bug, but that was done after the time of the 0.2.0 release, so this is why we still encounter it.
Until the next release comes out, the workaround will be to delete any empty folders from the App. You can do that by the following procedure:
Extract the downloaded file to any convenient location on your computer.
Open a command line terminal in the folder you extracted ADB to.
Type the following command at the command line prompt in the terminal:
./adb shell
Press the Enter key.
ADB should now successfully open a shell on the Linux machine of the UNO Q, as indicated by the changed terminal prompt. Something like this:
arduino@foo:/$
B. Make a Backup of the App
Just to be safe, it is a good idea to make a backup copy of the App before proceeding. If you already have a backup mechanism in place, just use that. Otherwise, you can follow these instructions to save a copy:
Type the following command at the command line prompt in the "Terminal" window:
ls ~/ArduinoApps
Press the Enter key.
A list of the folders of your Apps will be shown.
Type the following command at the command line prompt in the "Terminal" window:
tar --create --file="$HOME/app-backup.tar" --directory="$HOME/ArduinoApps" <App folder>
Replace the <App folder> placeholder in the command with the name of the folder of the broken App, as shown in the output from the ls command you ran in step (2).
Press the Enter key.
C. Remove Empty Folders From App
Type the following command at the command line prompt in the "Terminal" window:
ls ~/ArduinoApps
Press the Enter key.
A list of the folders of your Apps will be shown.
Type the following command at the command line prompt in the "Terminal" window:
cd ~/ArduinoApps/<App folder>
Replace the <App folder> placeholder in the command with the name of the folder of the broken App, as shown in the output from the ls command you ran in step (2).
Press the Enter key.
Type the following command at the command line prompt in the "Terminal" window:
find . -type d -empty -delete
Press the Enter key.
Please let us know if you have any questions or problems while following those instructions.
Now restart Arduino App Lab (it won't recognize the change to the App until you do this). Hopefully the App will now be in a functional state.
Now app-lab gets murdered by the oom-killer: (As a first try to free some memoryI restart docker and arduino-app-cli via systemctl, but that doesnt help)
Trying to run app-lab on an "big" computer and connect via network to the uno q results to this:
journalctl:
Nov 14 15:42:09 uno-q-first sudo[1948435]: pam_unix(sudo:session): session opened for user root(uid=0) by (uid=1000)
Nov 14 15:42:16 uno-q-first sudo[1948435]: pam_unix(sudo:session): session closed for user root
Nov 14 15:42:18 uno-q-first NetworkManager[463]: <info> [1763131338.0915] audit: op="radio-control" arg="wireless-enabled:on" pid=1948492 uid=1000 result="success"
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:27 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:28 uno-q-first sshd-session[1948376]: error: no more sessions
Nov 14 15:42:39 uno-q-first systemd[1]: systemd-localed.service: Deactivated successfully.
Nov 14 15:43:31 uno-q-first sshd-session[1949089]: Invalid user toad from 192.168.230.2 port 42244
Nov 14 15:43:37 uno-q-first sshd-session[1949089]: Connection closed by invalid user toad 192.168.230.2 port 42244 [preauth]
Nov 14 15:43:45 uno-q-first sshd-session[1949184]: Accepted publickey for arduino from 192.168.230.2 port 51678 ssh2: RSA SHA256:rw3QPQZFVoIfWIZ317WKYmV7/TUAorpOGzt/lhkoig8
Nov 14 15:43:45 uno-q-first sshd-session[1949184]: pam_unix(sshd:session): session opened for user arduino(uid=1000) by arduino(uid=0)
Nov 14 15:43:45 uno-q-first systemd-logind[407]: New session 79 of user arduino.
Nov 14 15:43:45 uno-q-first systemd[1]: Started session-79.scope - Session 79 of User arduino.
Maxsessions are raised:
arduino@uno-q-first:~$ sudo grep MaxSe /etc/ssh/sshd_config
[sudo] password for arduino:
MaxSessions 50
arduino@uno-q-first:~$
Console out from app-lab: (On the "big" computer)
$ ./Downloads/arduino-app-lab
Overriding existing handler for signal 10. Set JSC_SIGNAL_FOR_GC if you want WebKit to use a different signal
ERR | failed to open app asset /home/arduino/ArduinoApps/copy-3-of-home-climate-monitoring-and-storage/assets/docs_assets/hardware-setup.png: ssh: rejected: connect failed (open failed)
ERR | failed to open app asset /home/arduino/ArduinoApps/copy-3-of-home-climate-monitoring-and-storage/assets/docs_assets/launch-app.png: ssh: rejected: connect failed (open failed)
ERR | failed to open app asset /home/arduino/ArduinoApps/copy-3-of-home-climate-monitoring-and-storage/assets/docs_assets/climate-monitoring.png: ssh: rejected: connect failed (open failed)
Not really, I worked with linux machines that should not reboot without announcement.
Rebooting machines is really the last effort to me.
But I try, stay tuned.
No success:
$ ssh -X arduino@192.168.230.28
Linux uno-q-first 6.16.7-g0dd6551ae96b #1 SMP PREEMPT Tue Sep 23 12:46:06 UTC 2025 aarch64
The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.
Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Fri Nov 14 15:43:45 2025 from 192.168.230.2
arduino@uno-q-first:~$ app-lab
(process:1181): Gtk-WARNING **: 15:55:36.961: Locale not supported by C library.
Using the fallback 'C' locale.
Overriding existing handler for signal 10. Set JSC_SIGNAL_FOR_GC if you want WebKit to use a different signal
libEGL warning: DRI3 error: Could not get DRI3 device
libEGL warning: Ensure your X server supports DRI3 to get accelerated rendering
(process:1221): Gtk-WARNING **: 15:55:39.130: Locale not supported by C library.
Using the fallback 'C' locale.
** (WebKitWebProcess:1221): WARNING **: 15:55:40.318: Can't connect to a11y bus: Could not connect: No such file or directory
ERR | failed to open app asset /home/arduino/ArduinoApps/copy-3-of-home-climate-monitoring-and-storage/assets/docs_assets/climate-monitoring.png: no board connection available
ERR | failed to open app asset /home/arduino/ArduinoApps/copy-3-of-home-climate-monitoring-and-storage/assets/docs_assets/hardware-setup.png: no board connection available
ERR | failed to open app asset /home/arduino/ArduinoApps/copy-3-of-home-climate-monitoring-and-storage/assets/docs_assets/launch-app.png: no board connection available
Killed
arduino@uno-q-first:~$ uptime
15:56:52 up 2 min, 1 user, load average: 1.90, 1.04, 0.41
arduino@uno-q-first:~$ free -m
total used free shared buff/cache available
Mem: 1740 375 1227 32 241 1365
Swap: 870 329 540
arduino@uno-q-first:~$
# during running app-lab:
arduino@uno-q-first:~$ vmstat -w 1
--procs-- -----------------------memory---------------------- ---swap-- -----io---- -system-- ----------cpu----------
r b swpd free buff cache si so bi bo in cs us sy id wa st gu
1 0 143244 326184 12576 760504 2701 4961 8363 5603 1005 2 8 7 85 1 0 0
1 0 143244 324228 12576 760504 0 0 0 0 1184 1619 9 3 88 0 0 0
0 0 143244 324384 12576 760504 0 0 0 0 132 108 0 0 100 0 0 0
0 0 143244 326372 12584 760496 0 0 0 48 234 195 0 0 100 0 0 0
4 1 143244 322272 12864 760480 0 0 276 12 1086 1622 7 3 90 0 0 0
3 0 143244 320752 12868 752908 0 0 64 0 5054 7237 28 14 57 0 0 0
3 0 143124 309852 12868 754024 120 0 148 0 3053 3226 20 18 62 0 0 0
0 0 143124 304900 12868 756456 0 0 0 0 2439 2712 11 15 74 0 0 0
0 0 143124 308572 12868 756456 0 0 0 0 1432 1817 8 4 88 0 0 0
0 0 143124 310968 12868 756456 0 0 0 0 230 178 0 0 99 0 0 0
7 0 143044 293708 12868 759836 80 0 1224 0 2723 3515 35 11 54 1 0 0
1 0 143044 275032 13072 764872 0 0 332 0 4269 6010 47 21 31 1 0 0
9 1 143044 33156 13088 722844 0 0 29064 0 7642 9471 63 30 6 1 0 0
9 0 147284 30284 12436 421784 0 2996 10612 2996 8122 5753 54 45 1 0 0 0
8 0 258944 56936 2576 130424 5484 72292 11772 72356 5059 6261 32 67 0 0 0 0
10 0 504764 58392 2400 130944 11552 228976 32888 228976 3422 5083 16 83 0 1 0 0
8 0 734972 60928 2448 123480 10564 232368 47148 232380 6259 7463 12 87 1 0 0 0
8 3 891204 22952 2176 58712 27960 185332 85044 185336 12197 8630 10 86 1 2 0 0
15 9 891204 23400 2112 57964 828 980 658692 980 5004 15480 0 93 2 5 0 0
38 1 884104 22552 2160 62548 1272 9212 1171188 9208 29801 108695 0 99 1 0 0 0
2 3 491412 1145804 2596 203632 25136 7928 150696 8072 14585 118243 2 85 7 6 0 0
0 0 357204 1229000 2596 176760 26112 0 56396 0 2389 2873 6 13 75 7 0 0
0 0 357116 1228280 2596 177640 88 0 968 0 354 342 0 0 99 0 0 0
0 0 357116 1236300 2596 177640 0 0 0 0 108 87 0 0 100 0 0 0
^C
arduino@uno-q-first:~$
Is there some possibility to enable more verbose debugging output from app-lab?
Please note the raised run-queue shortly before the crash in the vmstat output, maybe this could be related by extensive swapping.
I tried it as an alternative for using app-lab on a "big" computer to get rid of these ssh errors.
I want to make shure that these problems are not related to ssh.
And mdns/avahi drives me nuts, and there is no possibility to connect to the board by name, and the connection does not use a running ssh-agent.
Those SSH errors are actually something new; we have never experienced them before. Can you please describe your scenario for the Uno Q? Where are all those SSH sessions starting from? Are they from an SSH-based app running on your PC?
Is the App Lab from your PC working with the Uno Q via network?
Do you have any firewall rules filtering UDP traffic on port 53? On your Linux host, double-check libnss-mdns is installed and configured correctly. Try running
avahi-browse -d local _arduino._tcp --resolve -t
Other avahi-browse commands may help troubleshoot mdns issues.
I have an update to share on this . The fix I mentioned above is in the newly released version 0.2.4 of Arduino App Lab. So, after updating Arduino App Lab, you should be able to put your Apps under version control in Git repositories without any adverse side effects. And likewise problems won't be caused by other operations that produce empty folders.
The new version is provided for download from the "Software" page:
This procedure is not intended to solve the problem. The purpose is to gather more information.
. The fix I mentioned above is in the newly released version 0.2.4 of Arduino App Lab. So, after updating Arduino App Lab, you should be able to put your Apps under version control in Git repositories without any adverse side effects. And likewise problems won't be caused by other operations that produce empty folders.