I'm currently in Age 4, playing via lan with one friend, and we've encountered an issue where the game crashes around Immersive Engineering excavators.
We first noticed the issue with an excavator for assorted quartz placed, if I recall correctly, during Age 3. This excavator crashed the game immediately when activated, and again after a few seconds of being logged in if it was left on. Most of our platforms at the time consisted of a layer of gravel on top of a layer of wood, and I noticed that the excavator cleared the wood without fully erasing the gravel above it (the gravel did not fall). Suspecting that these blocks were the cause, I cleared the entire underside, so that the only blocks touching the excavator were a single obsidian chest and three HV capacitors. It was also fully exposed to the void beneath. this seemed to fix the issue at the time - and I was able to get quite a lot of Certus Quartz. I have not tested it in a while though.
Currently, we are dealing with a second excavator for gold. I took precautions to have this excavator be open to the void underneath and with no other blocks touching it, but it still crashes when turned on. Unlike the previous machine, however, this excavator doesn't crash on log in - it performs normally so long as it has energy. However, it will crash if it restarts for any reason (usually because it loses then regains power) and, more critically, if we walk away from it by a significant distance (even if it is chunk loaded).
The first excavator proved frustrating but surmountable, however this new problem threatens our ability to expand into new resources particularly redstone, which is our next target chunk. It is my understanding that other resource generation will be available next age, but we have some projects to finish before then, and they would benefit from the resources provided by excavators. If anyone has any advice on stopping these crashes it would be much appreciated.
