Internal server error (500)! Can't open or download any PDF on Document Cloud anymore! Please help!

hello,

please help me, I can not open or download PDFs on my document cloud anymore! All my important University files are on adobe document cloud!

I open https://cloud.acrobat.com/  and the folder structure appears as usual. But when I open it 'Cannot preview filetype appears' where the PDF should be shown.

When clicking on 'download' a small windows says: 'Internal server error (500)'. 'Your request could not be completed due to an internal server error.'

Opening a file in the program acrobat reader (of my PC) it also says: ' There was an error opening this document. A file error has occurred'. For all of my files!

On my android tablet I cannot open any files either! What can I do to??

Best Regards

An