Forum vb3.8.4 to vb4.0.1 error

[محروم.كوم]

I'm getting this error message on the upgrade. any idea how to fix it?? Or what is needed to be done to fix it??

Quote:

Step 8) Attachment System Alterations (5/5)

• Altering attachmenttype Table (1 of 3)
• Altering attachmenttype Table (2 of 3)
• Altering attachmenttype Table (3 of 3)
• Altering albumpicture Table (1 of 1)
• Altering socialgrouppicture Table (1 of 1)
• Altering usercss Table (1 of 1)vB_Database_Alter: fetch_table_info() has not been called successfully.
  Incorrect key file for table 'usercss'; try to repair it

__DEFINE_LIKE_SHARE__