Bluno M3 V 2.2 unknown error when uploading a sketch !!

Using Arduino Programming Questions
#1

Hi,

I purchased a Bluno M3 from DFRobot, I installed the required IDE and driver but everytime I try to upload a sketch I get this error message:

serial_read1byte had problem, exiting
: No error
WARNING: trycount in serial_read1byte = 2
WARNING: trycount in serial_read1byte = 3
WARNING: trycount in serial_read1byte = 4

Anybody knows what it means ? I can't find any information on this type of error !!

Thanks !

#2

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#3