Happened to me 4 times I place down the gateway and let my mob crushers do the work for me, around round 50-80 the portal explodes and says
"the gateway imploded because a entity was removed without being killed" There might be mod conflicts im playing atm 10 so something might be messing with the spawn of some of the bosses I even placed down some ender inhibitors to stop stuff from teleporting around and it still didnt work
I just want the sigil of supremacy but the game is making it really hard to do it.... plz fix <3

Teleporting generally will not cause that issue to trigger, as the entity will be moved back within the gateway bounds if it moves outside. This error can only occur if another mod physically deletes the entity without issuing a kill credit for it.

Due to the length of this gateway I might flip the rule to allow discarding for it to ON to mitigate.

Teleporting generally will not cause that issue to trigger, as the entity will be moved back within the gateway bounds if it moves outside. This error can only occur if another mod physically deletes the entity without issuing a kill credit for it.

Due to the length of this gateway I might flip the rule to allow discarding for it to ON to mitigate.

We found out that it was the shiny mod, we turned shiny chance down to 0% and that seemed to fix the issue

Filed JDKDigital/shinymobs#6

When it comes to conflicts between two different mods, is it the modpack thats suppose to fix it or the mod itself?

Usually it is up to the modpack to diagnose. Who is responsible for fixing it depends on the nature of the fix. In this case it requires a code change from that mod.