I think I found something? I am experiencing similar issues, and I just saw this in the Planter mod: If you are using the beta update version of Fallout 4 then all your mods will get disabled, and the data file manager won't open up either. If you still want to use mods on the beta version, you can use either one of these methods: MANUAL PLUGIN.TXT ENTRY: Locate your plugins.txt file in your AppData/Local/Fallout4 folderThe AppData folder can be found in LocalDisk(C:)/Users/[YourUsername]/AppData Folders” Add the name of the esp (including the .esp part) at the bottom of that txt, save it and then set it to read only. NEXUS MOD MANAGER: Start the game-launcher, THEN start the NMM and enable all the plugins. Then press start in the FO4 Launcher. It should work, but you will have to repeat this every time you want to play FO4 for now. Just about to test this, but wanted to share first.