When the player teleports to another world by climbing/falling this is the result: https://pastebin.com/R7jKGGHq

Take a look at the full log. In there you will see a line that says "[main/WARN] [tfc]: You are not running an official build. Please do not use this and then report bugs or issues."

• The build is from https://jenkins.dries007.net/view/TFC//job/TerraFirmaCraft/
• The line you told me to look for is not in the log
• I'm the author of V10verlap trying to track this mod incompatibility down before it gets widely used

This crash is not specifically a compatibility issue with your mod. This is an issue with changing dimensions as the same crash occurs when going through a nether portal. We are early in development so we've not addressed issues with other dimensions yet.