OS X: Change sharing-only account to 'normal' account

Somehow, OS X changed my main user account to sharing-only. This means that all data in the user folder is still existent on the disk, I can't login to that user. Is there a way to revert a sharing-only user to a normal account.

Solution 1:

• Open the Users panel in Preferences
• Unlock the panel (if necessary)
• Right-click on your changed account, select "Advanced Options..."
• Reassign a login shell and a home directory to the user if necessary
• Click on your changed account
• Enable Administrator option
• Wait for the user type changing to Admin in the user list
• Disable Administrator option again