I think you have a lot of addons.
While checking the bottom of the log, I saw that there were too many errors like:
ERROR: Brick datablock "Brick6x16Data" has the same uiname as "brick6x16x3BrickData" (6x16) - removing.
BackTrace: ->ServerSettingsGui::clickLaunchGame->[GameModeCycle]createServer->createServer->onServerCreated->verifyBrickUINames