I know this has been discussed and the solutions provided have not helped me.
My upload directory is the default and the permissions are already set to 777.
When writing a post, I get the above error just when clicking 'upload'. It never even opens the search box to retrieve the file I want.
I've tried creating a new folder and changing the upload directory to that with no luck.
Again, the permissions are already set to 777. Please help if you can. Thanks!