When I try to load minecraft with OpenBlocks-1.10.2-1.7.2-snapshot-787 and OpenModsLib-1.10.2-0.11.2-snapshot-492. This issue comes up nearly instantly and crashes the launcher.
https://pastebin.com/UpPskVRm

Your title isn't correct according to the pastebin.

This looks like a coremod conflict. What other coremods are you running, forge version etc.

https://pastebin.com/ikjybqbb
Feel free to look through it all. Only about 200 lines.

Does this occur with only Forge and OpenBlocks on these versions?

Something is corrupting EntityHorse, but with multiple core mods it could be a few suspects or a combination of.

I recommend testing first up with only Forge and OpenBlocks, and see if you can replicate the issue.

If you can not, we can safely say it's either another CoreMod or a conflict between multiple coremods.

A usual suspect to try next, Is OpenBlocks, Forge, and the version of SpongeForge you are using together.

If that works, then I'm not sure what to test next, as it could be any combination of CoreMods.

Looking at the other issue tracker, it looks like OpenMods/OpenModsLib#72 needs backporting to 1.10

It looks like you are running the 1.10 version of OpenMobLib on minecraft 1.12 ?!? , Either way this issue looks like it's been fixed in the latest 1.12 snapshot.

I'd advise using the latest OpenBlocks and OpenModsLib snapshot in order to fix this.

It looks like you are running the 1.10 version of OpenMobLib on minecraft 1.12 ?!? , Either way this issue looks like it's been fixed in the latest 1.12 snapshot.

Was exactly the problem. For me minecraft.curseforge.com caused this because the "download" button does not download the newest version of the core lib.``

looks like it was the 1.10 version of the mod.