Non readable error message about sublimerepl

[ChiCubed]

I know this was asked AGES ago, but I'll answer it for others' sake anyway.
The problem is that SublimeREPL has the wrong path for execution. To fix this, find the file path to your Groovy folder, and then go to Preferences -> Package Settings -> SublimeREPL -> Settings - User, then type this line:

{
"default_extend_env": {"PATH": "{PATH};THE_PATH"}
}

replacing THE_PATH with your Groovy filepath.