See more at FAQ.md
Unable to Join Multiplayer Server
Nuclearcraft issue, see here on how to bandaid fix it. Note that the reason for this not being default is that it in turn introduces some problems of it's own, mainly allowing some ingots to be unintentionally smelted in a furnace.
Gregtech machine GUI mostly missing
Most frequently found on the Large boilers and Rocket Scanner, this is a bug with Gregtech: Modern. There is nothing that can be done until the mod updates - feel free to try downgrading until then but you may encounter even more issues in the attempt.
KubeJS errors when updating on Prism Launcher
Update to Prism 9.0. Previous versions of Prism don't delete files from the previous version of Moni when updating, so any file that should be removed in a modpack update won't necessarily be deleted on your end. This can cause problems.
EMI and/or AE2 having issues with GregTech tools
These mods don't handle NBT or tool-based crafting perfectly all the time, so you may encounter this issue occasionally. Try to transition to Assemblers or other machines ASAP. Machine crafting also offers improved material efficiency over tool crafting
UI elements overlapping with EMI
Switch to a lower GUI scale or tweak EMI's UI configs to your liking. Alternatively, disable EMI temporarily using Ctrl + O
Game crashes when generating a superflat world.
Lost Cities has issues with forcing players to spawn in a Lost City, and crashes when attempting to generate a superflat. Remove the mod to generate a superflat until the issue is fixed.
Game crashes on MacOS
Remove Spark and ensure you are using an ARM64 version of Java 17 or higher
Mod versions do not match when connecting to server (example pictured here)
Odds are your config doesn't match the ones on the server. If the server is running on Hard Mode, make sure that you've updated your client too
GregTech textures are all switched around
GregTech uses dynamically generated textures - reloading your resource packs may break this. Restart your game to fix it
Monifactory contains multiple mods that are at different stages of completion - it is not uncommon for a bug to be caused by one of these mods instead of Monifactory specifically. If you are unsure whether a specific mod may be causing a bug, try to replicate the bug on a new instance with only the mods necessary to re-create the issue. If you can do this, then the bug should be reported to that mod's developers instead of those of Monifactory
The most frequent offenders are listed below:
Issues with Nuclearcraft: Neoteric
Nuclearcraft: Neoteric is not in a great state. Many features (including some aspects of fission reactors!) are incomplete or buggy
Issues with EnderIO Modern
EnderIO 1.20.1 is not feature complete - things may be missing, have bugs or cause crashes. If you encounter any issues, please properly isolate the issue and submit a bug report to the Github page above.
Issues with Gregtech CEu: Modern
GTM is being actively developed. You are likely run into bugs, but these are addressed relatively quickly. Please ensure you aren't creating a duplicate report before notifying the devs of an issue or submitting a bug report to the Github page above.
Issues with AE2
Although bugs with AE2 are infrequent, the AE2 team has shown little inclination to address bugs on 1.20.1, so your best option is to find a workaround after submitting a bug report to the Github page above.