Getting lots of errors

I am using rclone on windows and i setup encrypted remote to mega.nz. I am uploading folder that is about 10GB. I started the sync command with -v option so i can watch what is happening and after rclone uploaded about 500mb i started seeing lots of this error: ERROR : Failed to copy: upload file failed to create session: Object (typically, node or user) not found.
What this error mean? Is it caused by the server or it's something on my end?

rclone version is 1.51.0

I am using Windows 7 x64.

Using mega.nz cloud storage with encryption.

The command i am using is: rclone sync local_path mega-crypt:remote_path --exclude-from exclude.txt

The log file reveal to much personal info. Sorry, but i can't post it. If you need some specific info from it i will search the log.

That error comes from the server.

It might be worth setting --transfers 1 to see if that helps.