Hello everyone sorry for the delay on the post. I'll be starting the Beatsaber lobby in 30 minutes to give time to reinstall everything.

In order to play this time you will need to first update to 1.8 then download the latest mod assistant below.
https://github.com/Assistant/ModAssistant/releases
Use this to uninstall and reinstall core mods, including mapping extensions. Then run the IPA.exe that's in the root of your steamapps/common/beatsaber folder.

Once you have that you'll need to copy over the 1.8 patched version of the mod below.
https://cdn.discordapp.com/attachments/541338412771311646/693572535740137472/BeatSaberMultiplayerLite-7.1.5-bs1.8.0-28a00b7.zip