I was playing Medieval Minecraft v6.5 modpack, and after 1.5-2 hours the server has crashed with org.objectweb.asm.tree.analysis.AnalyzerException, and the stacktrace mentions this mod, so I thought I'd report it just in case.

Here's the full stacktrace: https://pastebin.com/bXymx1tb

Edit: Increasing stack limit to 1.5Mb using "-Xss1536k" parameter seems to fix the issue

You run out of memory

Seems like the issue was indeed with available ram. After updating the modpack and increasing memory limit the issue disappeared.