@leocg Sorry i am so dumpXD
PDF Viewer, Editor & Converter this extension was the problem...

Thanks for the fast help

@leocg Yes downloaded files work perfect

Only links to documents do not work

@leocg Its a link
And i dont know what a chromnium Browser is but it works on firefox and Google Chrome

@leocg File could not be loaded

Hey,
when i want to open pdfs in my opera Gx Browser, always comes this screen.....

Have anyone an idea?

PS: Sorry for bad Englich