Have been on server for 10+ days and just began crashing today. I can load up the pack and then attempt to join the server but when I get to Joining World it crashes with this: java.lang.IndexOutOfBoundsException: Index 1 out of bounds for length 1

The rest of the crash report can be found here: https://mclo.gs/sK8HQhp

I appreciate any help you can provide.