So I have 7-zip and when I used to play adventure maps they would come as files I could open with 7-zip but all the one I got (Woolington) is a rar file and cant open with 7-zip apparetnly. So I downloaded ADL compressor that could open rar files, so I installed it, dragged the file in, clicked start, then it said it was done but everything was exactly the same as it was before. Please help me.
What I do is if its not the right .[insertgenericfilenamehere] then I just rename it.
I have 7-Zip too, and when I use the new weekly snapshots, it will always name it minecraft.zip by default. Just rename the file minecraft.zip and it should be fine.