Server was obviously not working properly, all of the plugins were preventively disabled, including inventory management. If you had a smartphone that had a black screen and wouldnt turn on, would you throw it on the ground to see if it fixes? Because thats the same thing on this case.
So you shouldnt be online to play on it, it actually locks you in place warning you. Staying online and being persistent for no reason only makes it worse, you should wait for staff to handle it. I was at work and I could only fiz it hours later.
It will only be restored if you have a screenshot of it prior to the server issues.