I am now having the same problem. I managed to upload the first Blinks SOS sketch, without any problems. It now runs this sketch each time the motherboard is powered via USB instead of the simple Blink that the chip originally came with. I know therefore that all of the connections and soldering are correct. I cannot upload any other sketch however as it gives the same error as @alaa-badredine above has reported, i.e.:

…………… avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x05
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x05
Problem uploading to board. See https://support.arduino.cc/hc/en-us/sections/360003198300 for suggestions.

I have been through all of the checks given in at the website but still cannot find anything wrong with my set-up.
Any suggestions?
It’s stopping me from going on any further with all the other boards.

Michael