SamuelTulach
'No permakey found in response!' if firewall blocks the upload
My firewall (which is Windows Firewall together with Windows Firewall Control) blocked your program. The block generated the above misleading message. Once I told the firewall to grant access, everything worked. (That said: see #83.) So the message needs changing.
With default firewall settings, you should be asked if you want to allow connections from the program, so I presume you either have edited those settings or used some debloater/privacy tool that has changed it.
The aforementioned Windows Firewall Control is set to block a connection unless a rule explicitly allows it. My point though is as follows. When your program is blocked by a firewall and thus (I presume) receives no 'response' at all, then the error message that it (your program) gives would do well to be more informative.