File Upload with Multisites does not work any more

dear all
out of a sudden we are not able to upload any files anymore to concrete.
the message is always:

“Ungültiger Token. Bitte laden Sie die Seite neu und versuchen es noch einmal.” nothing more – cache deleted etc.

in the meanwhile i found out, that this only occurs to multisites – anyone an idea?

thank you very much!

in case anyone else has this problem, it was a wrong entry in the ht access file. :slight_smile: