Board Thread:Mod Discussion/@comment-6941549-20140409163403/@comment-17114085-20140409184708

Ok here is what you have to do. A few months ago the Nexus Mod Manager serve was down so I had to install all my mods manually. To do this first download the mod manually from the Nexus. Then open the NMM and click on the Mods tab. On there the first icon to the left is a puzzle piece with a green plus sign on it. Click on that, it is the Add Mod from file button. Then pick the .rar file of the mod you want to install. The NMM will add the file into the Mods tab under the Unassigned category(depends on if you use the default categories from the NMM or made your own.). Then click on the newly added mod and install. Works like a charm.

I don't know what you meant by Frostfall and OBIS not being able to add from file since I literatly just tested adding them from file by using the method above. You must have been doing it wrong.