Upon launch, the game fails to load a resourcepack due to what appears to be an encoding issue.  The pack name in question is "Isabella II × SuikaCraft 1.13," with the encoding error found with the character "×".

Removed resource pack file/Isabella II × SuikaCraft 1.13 from options because it doesn't seem to exist anymore

It will load the game with no resourcepack, but the resourcepack can be then loaded without error.  This occurs whether it is a .zip archive or a folder.

We tested this back through the snapshots, even with an empty pack.  Where this got even stranger is that it appears to affect back to vanilla 1.12, 1.12.1, and 1.12.2.  However, this does not affect a Forge installation in 1.12.2.  These versions do not give a warning in the log.