There's a problem with R2's modding engine right now; modders are advised to set mod type to "5".
This cannot be done via the PackFileManager, and I will not include it in the time being because as CA stated, this is a non-standard pack type we should not use.
Here's a little tool to do that anyway.
1. select "Yes" if you want to change to the intermediate type of 5.
Files with the mod type 5 cannot be opened by the PFM, so if you want to be able to edit them, choose "No" here to change it back.
2. choose the file you want to set the type for.
It will keep asking you for files, just cancel when you're finished.