1.2.5 is no longer supported.
However, that error means that the mod crashed, you need to check the terminal for the stacktrace of the mod that crashed.
First of all, you are an idiot; forge does not download any MC files at all.
Second, MCPatcher is broken, use MultiMC.
Third, what the hell are you talking about; Forge downloads no MC files at all. It is an API for MC, not a launcher!
You will likely break some forge hooks doing that though.
Instead the mod should be updated to use Forge's ASM functionality instead of using Player API.
They will *NOT* work together.
If there is a mod that works on ML but does not work on FML, then as per the big giant red words on the front page, post links to the mods and your forgemodloader log, as the big red text says.
Likely PlayerAPI is breaking things. Smart Moving could be made as a Forge basemod without PlayerAPI though.
But until then PlayerAPI will continue to break things.
There is no 4.0.0.2.4 version of Forge, please do not give incorrect information.
But regardless, make sure that you have the latest, at least 4.0.0.231.
Unsure if been any sound updates recently, but forge 200 is *ancient* and has many bugs, you should update to 131+, or better yet, always dev with latest.
Always use the latest right now. Recommended is not really a recommended and will not be until ML compatibility is fleshed out and bugs fixed. So for now, always use latest.