We initially had just one computer set up with a local Altium SVN and just added another Altium machine. Rather than set up a server, we thought it might be possible to just point the "Default Checkout Path" and "Repository Location" on the new Altium setup to the folders used by the old Altium setup over the local network.
Altium now does an interesting thing where all projects can be opened viewed and edited by either computer, and either computer can view and access prior commits, but only the original creator of the project can create fresh commits. The error that Altium gives is unable to connect to a repository at URL 'file///C:/Users/OtherUser/OneDrive/Altium%20SVN/Boardname'
Does anyone have any idea what is causing this error or how to fix it?
You should not use file:// access schema for enduser access to the remote repositories on network. You should deploy SVN server for this and use either svnserve's protocol or HTTP(S).