Using Futurepack with the scanner and researching the metal block, you if you click on the metallurgy, you crash the minecraft jar, thus you crash the inter world with you. this was found one the Epic Crafting: Origins pack, and originally tried with my mod, then yours, and the outcome was the same. There is not crash report, but I will upload all logs.
latest.log
FP-Latest.log

debug log in teamspeak 3.

cause by me, fixed in lastest

which item was in the scanner when this happened?

Also this was most likely caused by a custom Research by your addons. This is fixed in 26.4.43