Another likely cause is some mod popping up a message box before the white overlay fades out, making the message box invisible. In that case, just spam enter a few times to get out of the message box, and the game will continue as normal.
Still not a fan of the "flat" design. Like, at all. It just doesn't work well on any screen larger than a phone, and only serves to reduce the usability of the interface. Other than that, the layout of the site is nice, I suppose.
Please, please keep in mind that the majority of your users will browse the site on a 16:9 or even 21:9 monitor. Don't go thin and tall. Vertical space wasted = bad. Horizontal space unused = bad.
Using NMM I currently get 'Server Unreachable' timeout errors on all recently uploaded files on all servers. Except UK KENT, which just says 'There was an error downloading your file' and immediately aborts.