mjevans

Answering 3: Your mods should each list which version of Forge they are happy with. Most mods right now will either want a version of forge that ends in the build number 105-108 (use either 105 or 108) OR they will want a version of forge build 132 or higher (they just updated very recently). Otherwise you have an outdated mod and might have to look for older versions of some mods to find ones that work with the same forge build. Forge 105 and 108 require the client to have ModLoader; ModLoaderMP is replaced by server-side FML (which is included with Forge). Forge 109 and higher come with a replacement for ModLoader already installed; it's called FML. A2: You probably don't actually need or want to know, but it's critical for developers and trouble-shooters, which is why we ask for that thing in Q1, the stack trace. A1: A stack trace describes where in the program and within what sequence of events an error occurred. At a glance, you're either mod_Arrows 1.2.5 is for a different version of forge or you installed things incorrectly. Given that you don't know the number of failure points, the fastest way is to start your tests with just Forge and nothing else. Then add one mod at a time so you can tell which fails.