baemz

Ah, I see. I did actually manage to get it solved. What I realised was that WordPress most likely wasnt using any of the Windows accounts that I thought of. So I tried to grant all users write+read permission on the folder and it worked.

Thank’s for your answer Mark, but as I said in the original post, I’m sure that there is write-permission on the whole folder and the files within.
So this can’t be the issue unless there are some other hidden permissions I need to change. Worth to note is that I’m using a Windows Server 2012R2 enviroment.