I loaded the blink program onto the Zero using a Visualmicro GDB project successfully several times but this stopped working upon trying the debug feature. 

VS2015 Pop-ups were:

1.
Unable to start debugging. Unexpected GDB output from the command "2-target-select remote localhost:3333", localhost:3333: The system tried to join a drive to a directory or a joined drive.

2.
"monitor" command not supported by this target.

The final error message at the bottom of the output window is: 

"Error: unable to open CMSIS-DAP device 0x3eb:0x2157
Error: No Valid JTAG Interface Configured."

I then reverted to simply uploading the previously working Arduino project imported into VisualMicro the The final error message at the bottom of the output window is: 

Error: couldn't bind to socket: Address already in use.

Rebooting PC did not help. When the Zero reset button is held down the LED stays off but once released the previously load blink program resumes. Two quick presses has no effect, excepting that the blinking LED stays off whilst reset is pressed.

Both output listings attached.

In a Winmerge comparison of the two outputs the last page of this shows that there is a difference regarding quotes and modification of path names. For example:

o/share/openocd/scripts/" -f
hare/openocd/scripts/ -f

UPDATE

With Atmel Studio 7.0.790 and following https://learn.adafruit.com/proper-step-debugging-atsamd21-arduino-zero-m0/lets-g... it is possible to get the Atmel debugger running as shown in the adafruit link. This upgraded the Zero firmware to 3.0c (I think) before debugger started successfully.

Tim@Visual Micro wrote on Mar 4^th, 2016 at 5:59pm:


Unfortunately not. The full Output window is produced below, but the last part reads:

Upload failed
Open On-Chip Debugger 0.9.0-gd4b7679 (2015-06-10-22:24)
Licensed under GNU GPL v2
For bug reports, read
     http://openocd.org/doc/doxygen/bugs.html
debug_level: 2
Runtime Error: iants/ARDUIN~1/OPENOC~1/ARDUIN~1.CFG:21: Can't find interface/cmsis-dap.cfg
in procedure 'script' 
at file "embedded:startup.tcl", line 60
at file riants/ARDUIN~1/OPENOC~1/ARDUIN~1.CFG", line 21

A similar problem is occurring with Arduino.cc 1.6.7, described at https://forum.arduino.cc/index.php?topic=383688.0

####### Output window ###############

Compiling 'GDB02' for 'Arduino/Genuino Zero (Programming Port)'
Build folder: 
Summary: Header=1 Prototypes=3 Imports=0
Additional Defines: 
Architecture Tools: .3-2014q1/bin/
Sketchbook: file:\\\C:\Users\me\Documents\Arduino
Sketch Include Paths
Include Path 'C:\Users\me\Documents\Visual Studio 2015\Projects\GDB02\GDB02'
Core Include Paths
Include Path arduino'
Include Path ts\arduino_zero'
8.3-2014q1\bin\arm-none-eabi-g++"  -mcpu=cortex-m0plus -mthumb -c -g -Os -w -std=gnu++11 -ffunction-sections -fdata-sections -fno-threadsafe-statics -nostdlib --param max-inline-insns-single=500 -fno-rtti -fno-exceptions -w -x c++ -E -CC -DF_CPU=48000000L -DARDUINO=10607 -DARDUINO_SAMD_ZERO -DARDUINO_ARCH_SAMD -D__SAMD21G18A__ -DUSB_VID=0x2341 -DUSB_PID=0x804d -DUSBCON -DUSB_MANUFACTURER="\"Arduino LLC\"" -DUSB_PRODUCT="\"Arduino Zero\""     CMSIS/Include/" Device/ATMEL/"  s\arduino" ants\arduino_zero" cpp" -o "nul"
Build Core Paths: rduino
Using previously compiled file: pp.o
8.3-2014q1/bin/arm-none-eabi-gcc" "-LC:\Users\me\AppData\Local\V.Micro\Arduino\Builds\GDB02\arduino_zero_edbg" -Os -Wl,--gc-sections -save-temps ants\arduino_zero/linker_scripts/gcc/flash_with_bootloader.ld" bg/GDB02.ino.map" --specs=nano.specs --specs=nosys.specs -mcpu=cortex-m0plus -mthumb -Wl,--cref -Wl,--check-sections -Wl,--gc-sections -Wl,--unresolved-symbols=report-all -Wl,--warn-common -Wl,--warn-section-align -o ino.elf" cpp.o" -Wl,--start-group -lm " -Wl,--end-group
8.3-2014q1/bin/arm-none-eabi-objcopy" -O binary ino.elf" ino.bin"
Binary sketch size: 8,156 bytes (used 3% of a 262,144 byte maximum) (8.03 secs)
 
Uploading to I/O board using 'COM17'
Uploader started for board Arduino/Genuino Zero (Programming Port)
Upload method will be: bootloader
Uploading via Bootloader 
\bin\openocd.exe -d2 -s o/share/openocd/scripts/" -f iants/ARDUIN~1/OPENOC~1/ARDUIN~1.CFG -c "telnet_port disabled; program .ino.bin}} verify reset 0x00002000; shutdown"
Upload failed
Open On-Chip Debugger 0.9.0-gd4b7679 (2015-06-10-22:24)
Licensed under GNU GPL v2
For bug reports, read
     http://openocd.org/doc/doxygen/bugs.html
debug_level: 2
Runtime Error: iants/ARDUIN~1/OPENOC~1/ARDUIN~1.CFG:21: Can't find interface/cmsis-dap.cfg
in procedure 'script' 
at file "embedded:startup.tcl", line 60
at file riants/ARDUIN~1/OPENOC~1/ARDUIN~1.CFG", line 21

Tim@Visual Micro wrote on Mar 5^th, 2016 at 4:53pm:


Upload on Arduino IDE 1.6.7 gives the same error; it also fails to burn a bootloader, see https://forum.arduino.cc/index.php?topic=383688.0

However, I can run Atmel Studio 7.0.790 in debug and step through the code, so the Zero is working. I presume the bootloader is lost once I uploaded the program in AS7 but the Visualmicro debug failed as described above before I ran the Zero in AS7.

In conversations with Atmel some weeks ago, as at 13/01/15 AS7 did not support Due/Zero code imported from Arduino.cc IDE. Hence it is unlikely that the Zero board was used in AS7 as it was not possible to select this board in  AS7 at the time. The Zero was not supported in 1.6.7 at that date either. For these reasons I have not knowingly used the Zero until trying to debug in Visualmicro as reported above.

Tim@Visual Micro wrote on Mar 6^th, 2016 at 1:29pm:


Attempts to burn a bootloader in 1.6.7 are detailed in https://forum.arduino.cc/index.php?topic=383688.0

For Visualmicro just did the following:

VisualMicro.programmer= Atmel EDBG "Always Use Programmer For Upload" ticked and also "Always Use Programmer For Upload" unticked

(In Control Panel\Hardware and Sound\Devices and Printers,  EDBG CMSIS-DAP does not show a port number but it shows COM18 in Visualmicro)

In both cases, same error:
###################
Burning a new bootloader
Burning bootloader to board 'Arduino/Genuino Zero (Programming Port)' using 'Atmel EDBG'
\bin\openocd.exe -d2 -s o/share/openocd/scripts/" -f ts/arduino_zero/openocd_scripts/arduino_zero.cfg" -c "telnet_port disabled; init; halt; at91samd bootloader 0; program oaders/zero/samd21_sam_ba.bin}} verify reset; shutdown"
Open On-Chip Debugger 0.9.0-gd4b7679 (2015-06-10-22:24)
System.Exception: Burn bootloader failed with an exception ---> Visual.Micro.MiroAppAPI.debug.RunnerException: Upload failed

   at Visual.Micro.MiroAppAPI.debug.Uploader.executeUploadCommand(ICollection commandDownloader, String workingPath)
   at Visual.Micro.MiroAppAPI.debug.Uploader.executeUploadCommand(ICollection commandDownloader)
   at  programmerPrefs, String programmer)
   --- End of inner exception stack trace ---
   at  programmerPrefs, String programmer)
   at Visual.Micro.MiroAppAPI.debug.AvrdudeUploader.burnBootloader(Board boardPreferences, String programmerName)
Burn failed
Licensed under GNU GPL v2
For bug reports, read
     http://openocd.org/doc/doxygen/bugs.html
debug_level: 2
Runtime Error: s/arduino_zero/openocd_scripts/arduino_zero.cfg:21: Can't find interface/cmsis-dap.cfg
in procedure 'script' 
at file "embedded:startup.tcl", line 60
at file ts/arduino_zero/openocd_scripts/arduino_zero.cfg", line 21
###############

The various attempts to burn a bootloader in 1.6.7 are detailed in the link given above,  https://forum.arduino.cc/index.php?topic=383688.0

This include using an Atmel ICE. All failed.

However this does not address the OP, namely the error which occurred when trying to debug in Visualmicro.

Also, can your new debugger be used with an Atmel ICE and some other board such as a Due?

Thanks

Tim@Visual Micro wrote on Mar 7^th, 2016 at 10:41am:


As the standard 1.6.7 upload failed I tried Atmel ICE as an alternative.

Tim@Visual Micro wrote on Mar 7^th, 2016 at 10:41am:


1. I loaded several variants of Blink onto Zero with Visualmicro to demonstrate that it was uploading successfully.
2. Tried Visualmicro debug, which failed as per OP.
3. I loaded several variants of Blink onto Zero with Atmel Studio 7  to demonstrate that it was uploading successfully.
4. Ran debug successfully in Atmel Studio 7.
5. Attempted to burn bootloader in 1.6.7, as detailed in https://forum.arduino.cc/index.php?topic=383688.0
6. Attempted to burn bootloader in Visualmicro as detailed in above posts.

Tim@Visual Micro wrote on Mar 7^th, 2016 at 10:41am:


There appears to be something wrong with my setup of 1.6.7 which is why raised https://forum.arduino.cc/index.php?topic=383688.0

Are you saying that even though  step 1. above was successful it does not necessarily follow that the debug would also work?

Thanks

Thanks.

Can your new debugger be used with an Atmel ICE and some other board such as a Due? I need to step through code so the old debugger does not suit.

Tim@Visual Micro wrote on Mar 7^th, 2016 at 1:47pm:


I successfully uploaded blink variants to a Due using 1.6.7 and also with Visualmicro GDB.

Debug in Visualmicro simply loads the latest blink program onto the Due board, it does not stop at the breakpoint
digitalWrite(13, HIGH); 

The Atmel ICE does not show up Visualmicro.Programmer, though it is visible at Control Panel\Hardware and Sound\Devices and Printers though it is not obviously assigned to a particular port.

What is the correct set-up to step through code on a Due in Visualmicro?

Tim@Visual Micro wrote on Mar 7^th, 2016 at 6:41pm:


Attached.