So I updated a newer version of forge (10.13.1.12.15) and I put all my mods back into the mod folder and said that I needed a newer version of forge, and the version it said to get wasn't even a version yet. So I went through each mod to see which one caused the problem and it was tinkerers construct. Can someone please tell me how to fix this because I can't play modded minecraft without having tinkerers construct a part of it. Thank you.

10.13.1.12.15 That is a invalid version you have one to many .'s in there.

Anyways if it says you need a new version of forge then download the version it tells you: http://www.minecraftforge.net/forum/index.php?action=files

oh, sorry I meant .1215 no dot between the 12 and 15. but even when I tried to use the latest version it still didn't work

http://files.minecraftforge.net/maven/net/minecraftforge/forge/index_1.7.10.html

10.13.1.1215 exists, it's old as shit, but i exists. If you have a mod that explicitly requires that version and doesn't support newer ones you should go yell at the mod creator to update.

I just tried to play with the mod again and now it says I need the same except instead of 1215 it says it needs 1217

Then install 1217 -.- this is a simple problem, Follow the directions.

Or just update to the latest/recommended should work for all mods you have and if they do not yell at the mod authors to update.

Now, do you have a issue or are you just gunna repeat the same thing over and over?