I'm using 1.12.2, Forge version:forge-1.12.2-126.96.36.19905-universal. The current recommended version.
When I launch the game using forge with my mods, I can't load into ANY servers, Vanilla or modded. I get stuck on the screen that says, "Logging In," and it never goes past that. My friend is also having the exact same issue.
It could be something to do with the amount of mods we have, I'm currently investigating. We have roughly 10 fairly small mods
UPDATE: With no mods in the .minecraft folder, I load in just fine, but with the mods I get stuck at the logging in page. Its likely something to do with memory or something but I've got 16g of RAM, and I don't know what I could do.