I can not change a file attribute from 0600 to 0755 due the rights?

Please reach out to Nitrado Support for further investigation.

Typically those permissions are restricted or the directory it is in, is restricted. Only Support can help you.

Thank you.

Why exactly would it matter in the first place?

600 should be just fine for practically anything you want to do.

Why does it need 755 and not 700 or 600?

I don't see a reason for that.

600 means the owner has read and write permissions. 755 means everyone has read and execute permissions and the owner has write permissions additionally. Though to my knowledge the execute permissions are ignore in that case.

So what exact error are you getting and where are you getting it?