So I downloaded some mods on minecraft and ran them on my laptop. Friend downloaded the same mods. My game is working just fine. However, his game refuses to launch after pressing play, even with just one mod. After reading some posts we've both reverted back to the old client, the one that was used in 1.7.2. Mine did not work until I reverted back to the old client. His is still not working though. The mods are all for the same version of minecraft that we're running and they don't conflict with each other, so it must have something to do with the computer itself. I'm not the best with this kind of stuff, but it feels like he needs to update something on his pc, rather than the mods being the problem. Screenshot of the crash report:

You won't really find help for 1.7.2 here, old versions of forge are no longer supported here. Upgrade to a newer version (1.10.2+ I believe), and repost with logs if you're having issues, and someone will probably have some help for ya

Just now, Ugdhar said:

You won't really find help for 1.7.2 here, old versions of forge are no longer supported here. Upgrade to a newer version (1.10.2+ I believe), and repost with logs if you're having issues, and someone will probably have some help for ya

I'm reasonably sure I'd have the same problem using a newer version. It seems like he needs to update or change something to run it, not sure what though.

You wouldn't have the same problem with a newer version as this was fixed in the latest 1.6.4 and the early 1.7.10s so just update. Reading the eaqs also helps as this exact error is described in it.