I am trying to upload the GuiXT files to our web repository. Why have I been getting an RFC error ever since I changed the Scripts directory to point to the web repository?

I suggest you first check that the RFC user exists in the right client: The RFC logon for SAPWR access is done in client 000, unless you specify "Script download via current client"  in GuiXT profile

Alternatively, you can create the RFC user in a specific client xyz, and specify

SAPWR,client=xyz:ZGUIXT

instead of

SAPWR:ZGUIXT

as Directory1. The RFC logon is then always performed in client xyz. Compared with the "Script download via current client"  this has the advantage that the logon script will be executed as well. This is not done in the case of "Script download via current client", since the client is not yet known when the logon screen is displayed.