On the outside chance this might fix it for you JLaine, re-download the zip file again, extract it into the folders they are in the zip file: Compress, IO, and Digest and upload them to your ubbcgi/Modules directory and let me know if the error messages subside at least a little bit.
Donate to UBBDev today to help aid in Operational, Server and Script Maintenance, and Development costs.
Please also see our parent organization VNC Web Services if you're in the need of a new UBB.threads Install or Upgrade, Site/Server Migrations, or Security and Coding Services.