We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.
You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
They don't know what causes it so it is unknown when it will be fixed. There are already several threads about this in the technical support forum, the bug-report forum and the general-discussion forum.