I'm assume that the exact error message began with "ERROR: Making mod directory ". The most likely reason for failure to create the mods directory is that you assigned a new path for the mods folder that required making more than one folder to reach the specified path. This problem is fixed in the Bugfix mod, but that won't help you right now. There are a few alternate solutions. You can try to change the path in the Mods menu beside the "Open Mod Folder" button to "user://mods/"(equivalent to ".../Strive/mods/" in the users appdata folder), you can create the exact folders needed to match the path specified in the Mods menu, you can delete the "progressdata" file (this will delete your gallery unlocks) to reset the path to the default, or you can edit globals.gd and replace one instance of "make_dir(" with "make_dir_recursive(".