This has been a pretty old bug I've experienced in buildcraft for a while now and it gets pretty annoying for such an awesome mod. From what I can tell, the solid collision box causes a crash when the chunks are un-rendered and re-rendered (Go out of view and then back in view). Rather the chunk loading is left as is, or assisted with chicken chunks chunk loader.

I am on 1.12.2 using forge 14.23.5.2847 using mod version buildcraft-all-7.99.24.5 downloaded from https://www.curseforge.com/minecraft/mc-mods/buildcraft with OptiFine_1.12.2_HD_U_F4 downloaded from https://optifine.net/home (May be rendering related) No shaders, no resourcepack

Video options:
options.txt
optionsof.txt
optionsshaders.txt

I have an intel i7-2600K 3.4GHz with 32GB of RAM using 26GB for the huge modpack its in so its comfortable with just enough ram but not too much.

JVM Arguments:
-Xmx26G -Xmn12G -d64 -XX:+DisableExplicitGC -XX:PermSize=256M -XX:MaxPermSize=512M -XX:ParallelGCThreads=2 -XX:+UseConcMarkSweepGC -XX:MaxGCPauseMillis=50 -XX:+UseStringDeduplication -XX:+UseCompressedOops -XX:+UseCodeCacheFlushing -XX:SoftRefLRUPolicyMSPerMB=10000 -Dfml.ignoreInvalidMinecraftCertificates=true -Dfml.ignorePatchDiscrepancies=true -Dfml.readTimeout=2140 -Duser.language=en -Duser.country=US

ps. I know this is a huge modpack, so there can possible be a million factors, but I have had this collision box issue in many other modpacks in many other versions of minecraft and the mod version

Also random screenshot of the crash screen if this helps:

crash-2020-03-02_03.51.04-client.txt

I can also provide the link to download the custom pack with ~580 mods if that would help

Thanks for the detailed information! Fortunately however the crash report contains enough information for me to try and fix this, so can you try the test release 7.99.24.6-pre.1, from the tests page to see if that fixes this?

I'll start testing it in my huge modpack and I'll report if there is any crashes, if I find none in a month of gameplay. then I'll assume its fixed

Ok, this should be fixed in the release 7.99.24.6.