AWS S3 communication is very sensitive to machine clock timestamps.
Therefore if the system clock of the machine that is using the upload tool is not set accurately the upload will fail with error message:
"An error occurred: Upload failed because local system time is set inaccurately, which makes it impossible to communicate with cloud. Please synchronize your system time"
Fixing the problem consists of setting the time/date in the machine correctly in relative to the geographical location of it.