The messaging interface has returned an unknown error. If the problem persists restart Outlook

Description: User gets message "The messaging interface has returned an unknown error. If the problem persists restart Outlook. Access is denied. Make sure the disk is not full or write-protected and that the file is not being used." when trying to reply to an email

[SWE] Det har uppstått ett okänt fel i meddelandegränssnittet. Starta om Outlook om problemet kvarstår. Åtkomst nekad. Kontrollera att disken inte är full eller skrivskyddad och att filen inte används"

Applies to: Outlook 2000/2002/2003

Solution:

1. Go to Start -> Run. Type in outlook.exe /cleanprofile. This will remove invalid profile keys and recreate default registry keys where applicable. After done, close Outlook

2. Go to Start -> Run. Type in outlook.exe /cleanviews. This will restore default views (you will use any custom views). When done, close Outlook.Reopen Outlook and test.