having a LOT of trouble with a custom arduino flashing app

so I'm trying to create a super smart nerf gun, which uses BLDC motors, ESC's and an arduino nano to control it all. Somebody made an application where you can configure settings, and then flash the arduino nano with your settings. it can be downloaded here: YouTube. I'm having trouble flashing my arduino nano's with the app. The app gives you an option to choose "use old bootloader". When I uncheck "use old bootloader, I get this error:

"C:\Users\steve\Downloads\Ultra-Arduino (2)\Supporting files\avrdude.exe" -q -patmega328p -carduino -PCOM5 -b115200 -D -Uflash:w:"C:\Users\steve\Downloads\Ultra-Arduino (2)\Supporting files\Ultra-Arduino.ino.hex":i

avrdude.exe: AVR device initialized and ready to accept instructions

avrdude.exe: Device signature = 0x1e950f

avrdude.exe: reading input file "C:\Users\steve\Downloads\Ultra-Arduino (2)\Supporting files\Ultra-Arduino.ino.hex"

avrdude.exe: writing flash (32670 bytes):

avrdude.exe: stk500_paged_write(): (a) protocol error, expect=0x14, resp=0x64

avrdude.exe: stk500_cmd(): programmer is out of sync

when I check "use old bootloader", it gives me this:

"C:\Users\steve\Downloads\Ultra-Arduino (2)\Supporting files\avrdude.exe" -q -patmega328p -carduino -PCOM5 -b57600 -D -Uflash:w:"C:\Users\steve\Downloads\Ultra-Arduino (2)\Supporting files\Ultra-Arduino.ino.hex":i

avrdude.exe: stk500_getsync(): not in sync: resp=0x00

avrdude.exe done. Thank you.

I've tried installing drivers, and I even burned a bootloader, and after I burned the bootloader I could flash the nano with the arduino IDE, but I NEED to use this app.

If I flash this nano with the IDE and I choose atmega328p (old bootloader) as the processor, I get this error:

Sketch uses 444 bytes (1%) of program storage space. Maximum is 30720 bytes.

Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xf0

avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0xf8

avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0xf0

avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0xfa

avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0xf8

avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0xf8

avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0xfa

avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0xf0

avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0xfa

avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0xf8

An error occurred while uploading the sketch

If I choose atmega328p, It uploads successfully.

I have another older arduino nano, and if I try it without checking "use old bootloader" I get:

"C:\Users\steve\Downloads\Ultra-Arduino (2)\Supporting files\avrdude.exe" -q -patmega328p -carduino -PCOM5 -b115200 -D -Uflash:w:"C:\Users\steve\Downloads\Ultra-Arduino (2)\Supporting files\Ultra-Arduino.ino.hex":i

avrdude.exe: stk500_getsync(): not in sync: resp=0x70

avrdude.exe done. Thank you.

I get the same error when I check use old bootloader.

When I try flashing this nano with the IDE, if I choose atmega328p, I get this error:

Sketch uses 444 bytes (1%) of program storage space. Maximum is 30720 bytes.

Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.

An error occurred while uploading the sketch

avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x78

avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x40

avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x1b

avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x38

avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x72

avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x18

avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x6e

avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x9a

avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x22

avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x83

if I choose atmega328p (old bootloader) It never finished flashing for some reason, idk it just takes a really long time, I'm tired of waiting.

I also tried a new cable, obviously same results.

what can I do? I really need to get this to work, I've been planning this for 5 months and I've spent like $200 on this. Big sad :(.

Have looked at the basic troubleshooting steps here?

For example, see the steps described under 'COMMON ISSUES' in the second post.

Unfortunately the website you got the custom app from seems to be offline, so it may be a while before anyone can help.