I'm no longer able to upload images to the NMS Discoveries wiki https://nms.miraheze.org/wiki/Main_Page
Each time I try to upload an image, I get the following error message: "Action failed. Could not open lock file for "X". Make sure your upload directory is configured correctly and your web server has permission to write to that directory."
All of the previously uploaded and previously working images are now showing as broken; that's everything under Special:ListFiles. Something has to be wrong on the host/server side of things as the issue only started this morning; it's been working fine even as recently as last night.