I have firefox as my default browser. However, when opening pdf documents, the default seems to be Microsof Edge. The problem is that on some websites, when I try to switch to Firefox as the default browser for downloading pdf files, the temporary file location can't be found, resulting in the browser continuously opening tab after tab very quickly in an attempt to open the file. I have no choice but to close the entire set of tabs (there is no time to logout of anything properly as the tab multiplication is very quick. Any help would be appreciated. I have 'unhidden' the files temporarily, and it seems that the file/folder location exists, so I can't understand why it can't place them there. I am not technical, so please keep the language as simple as possible.