Boron code not updating

Hi Ive started running into a problem when flashing my boron/s its happening to multiples boron devices.
i hit complie and flash and the following happens and says successfull but there is a line that concerns me. (see bottom)
Serial device PARTICLE_SERIAL_DEV : not available

The boron then try to connect to Particle cloud but goes into a debug mode. If i reset it, itgoes into debug again, but on the second or third time it gets stuck in DFU mode forever.
I unplug it & and plug it back in straight into DFU

We i started using a new code i got this problem, but i when back to code i know works still same issue.

Executing task: make -f ‘C:\Users\AGLOT.particle\toolchains\buildscripts\1.9.2\Makefile’ flash-user -s <

:::: PUTTING DEVICE INTO DFU MODE

Done.

:::: FLASHING APPLICATION

Creating d:/Particle/Code/Boron420mA/target/1.5.2/boron/platform_user_ram.ld …
Creating d:/Particle/Code/Boron420mA/target/1.5.2/boron/platform_user_ram.ld …
text data bss dec hex filename
14600 192 1440 16232 3f68 d:/Particle/Code/Boron420mA/target/1.5.2/boron/Boron420mA.elf
dfu-suffix (dfu-util) 0.9

Copyright 2011-2012 Stefan Schmidt, 2013-2014 Tormod Volden
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/

Suffix successfully added to file
Serial device PARTICLE_SERIAL_DEV : not available
Flashing using dfu:
dfu-util 0.9

Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2016 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/

Opening DFU capable USB device…
ID 2b04:d00d
Run-time device DFU version 011a
Claiming USB DFU Interface…
Setting Alternate Setting #0
Determining device status: state = dfuIDLE, status = 0
dfuIDLE, continuing
DFU mode device DFU version 011a
Device returned transfer size 4096
DfuSe interface name: "Internal Flash "
Downloading to address = 0x000d4000, size = 14796
Download [=========================] 100% 14796 bytes
Download done.
File downloaded successfully
Transitioning to dfuMANIFEST state

*** FLASHED SUCCESSFULLY ***

Press any key to close the terminal.
Hi there :wave:

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Can you try flashing deviceOS and your application?

From the Command Palette (SHIFT + CTRL + P), run the following task.

Particle: Flash application & DeviceOS (local)

Also, this warning can be ignored.

Thanks this did fix it.