[SOLVED] Arduino Zero - Difficulties getting started

I am trying to get my new Arduino Zero working with some example sketches, but I'm encountering some difficulties. My primary interest in the Zero is with its USB host functionality (eventually I want to use it as a host for USB-MIDI keyboards), so the first example I tried was MouseController. After resolving a multiple libraries conflict, I was able to get the code to compile, but not to upload successfully. Here's the error message I'm getting:

Sketch uses 14,812 bytes (5%) of program storage space. Maximum is 262,144 bytes.
Open On-Chip Debugger 0.9.0-gd4b7679 (2015-06-10-19:16)
Licensed under GNU GPL v2
For bug reports, read
    http://openocd.org/doc/doxygen/bugs.html
debug_level: 0
adapter speed: 500 kHz
adapter_nsrst_delay: 100
cortex_m reset_config sysresetreq
target state: halted
target halted due to debug-request, current mode: Thread 
xPSR: 0x21000000 pc: 0x00000d4c msp: 0x200025d8
** Programming Started **
auto erase enabled
wrote 24576 bytes from file /var/folders/y8/wpn8r6pn5_b2tqkvr4sybzpm0000gn/T/build83b8cf44bdec7ba98b7746391a6c2f65.tmp/MouseController.ino.bin in 3.204736s (7.489 KiB/s)
** Programming Finished **
** Verify Started **
verified 14972 bytes in 1.240182s (11.789 KiB/s)
** Verified OK **
** Resetting Target **
shutdown command invoked

I also tried the basic Blink example, just to try to get anything working, and I got a different error:

Sketch uses 8,356 bytes (3%) of program storage space. Maximum is 262,144 bytes.
Open On-Chip Debugger 0.9.0-gd4b7679 (2015-06-10-19:16)
Licensed under GNU GPL v2
For bug reports, read
    http://openocd.org/doc/doxygen/bugs.html
debug_level: 0
adapter speed: 500 kHz
adapter_nsrst_delay: 100
cortex_m reset_config sysresetreq
Error: CMSIS-DAP command CMD_INFO failed.
Error: No Valid JTAG Interface Configured.

I'd greatly appreciate any assistance in getting the Zero working (especially as a USB host!)

Using the native USB port, try double tapping the Zero's reset button. This puts the Zero into bootloader mode, (you'll notice it will change COM port). Now try uploading the Blink sketch as usual.

Thereafter you should be able to upload sketches normally oncemore.

The first debug message you posted here is not an error : it shows that the chip has been succesfully programmed. Like Martin suggested, try to upload via the Native USB port by putting the device into bootloader mode (double tap on reset button). Are you using the Arduino.cc Zero, or the Arduino.org M0/M0 pro ? There is a difference between them and each wont work with others IDE.

I'm using an Arduino Zero from Arduino.cc with the Arduino.cc IDE, so this configuration should work. When I plug the cable into the Native USB port, the port never appears in the Ports menu, so I can't upload anything to the Zero. Clicking the reset button twice doesn't seem to change anything.

When I connect to the Programming port, I can compile the Blink example, but it still isn't giving the desired behavior. If AloyseTech's analysis of the first debug message is correct, I guess it's uploading:

Build options changed, rebuilding all

Sketch uses 8,356 bytes (3%) of program storage space. Maximum is 262,144 bytes.
Open On-Chip Debugger 0.9.0-gd4b7679 (2015-06-10-19:16)
Licensed under GNU GPL v2
For bug reports, read
    http://openocd.org/doc/doxygen/bugs.html
debug_level: 0
adapter speed: 500 kHz
adapter_nsrst_delay: 100
cortex_m reset_config sysresetreq
target state: halted
target halted due to debug-request, current mode: Thread 
xPSR: 0x21000000 pc: 0x00000d4c msp: 0x200025d8
** Programming Started **
auto erase enabled
wrote 24576 bytes from file /var/folders/y8/wpn8r6pn5_b2tqkvr4sybzpm0000gn/T/buildd5ae82e677127ac286f51de66781d807.tmp/Blink.ino.bin in 3.186927s (7.531 KiB/s)
** Programming Finished **
** Verify Started **
verified 8508 bytes in 0.727069s (11.428 KiB/s)
** Verified OK **
** Resetting Target **
shutdown command invoked

However, the LED on pin 13 is not blinking, it's still running the default fading pattern that it's been doing since I took it out of the package.

Try to connect to the programming port, and select Arduino/Genuino Zero Native USB port in the board menu. In the Programmer menu, select Atmel EDBG. Then, click on "Tools/Burn bootloader". After that, try to upload the Blink program via either Native or Programming port.

That's solved it, thanks so much! On to getting the USB Host functionality going...

I know by experience that sometimes, a bad programm can mess up the bootloader and brick your Arduino Zero. All you have to do is reburn the bootloader like I described... and correct the faulty program :)