Failing to upload to board.

[alidaf]

I can't seem to upload files to my SyPy boards any more.
I constantly get errors:

Uploading project (src)...
Not safe booting, disabled in settings

Reading file status
Failed to read project status, uploading all files
Creating dir lib
[1/6] Writing file boot.py
Failed to write file, trying again...
Failed to write file, trying again...
Filecheck failed
[2/6] Writing file lib/LTR329ALS01.py
[3/6] Writing file lib/SI7006A20.py
Failed to write file, trying again...
Failed to write file, trying again...
Filecheck failed
[4/6] Writing file lib/pycoproc.py
Failed to write file, trying again...
Failed to write file, trying again...
Filecheck failed
[5/6] Writing file lib/pysense.py
[6/6] Writing file main.py
Failed to write file, trying again...
Failed to write file, trying again...
Upload failed.: Filecheck failed Please reboot your device manually.
OKets Jun 8 2016 00:22:57

I've updated the firmwares but nothing helps.

[alidaf]

To fix this, change the options in PyMakr to "Safe boot before upload".