@realact I don't be sure, but I think I don't use a cache plugin. I have bougt today a new licence wpForo Advanced Attachments - Single Site License...

Sorry, but I don't understand. How can I clean up all caches? I have a new license, I think

Problem solved! Thanks very muchBest regards

@sofy This is the error message: Choose a files or drag and drop it here. Max file size 2KB Error: File is too big. Allowed size is: 2KB

Ok, thanks for all. I try to ask the Worpress Support about this. Thanks so much  

Ok  

When I click on my WP Admin, that it´s what happens. Instead of opening the administrator, it is redirected to the image screen 2 Image-2.png

The first image: Image-1.png

Sorry, but I can´t record with my pc. I try to send you images of all ok?

I have a problem with the record, one moment, please. I need to configure my PC previosly

I try to record now

  Instead, just try using Google Chrome and it works. Does the problem with Firefox have anything to do with it now?