This error is most commonly caused by plugins or addons that incorrectly set auto increment fields within vBulletin. Please remove your plugins or addons and verify that the database keys are set correctly.
It can also be caused by backing up a newer MySQL database with the "Compatibility Option" if this is the case, the MYSQL backup does not contain auto-increment information and the proper indexes are not created when the backup is restored.
Please run these queries to create the proper indexes in vBulletin.
ALTER TABLE `adminhelp` CHANGE `adminhelpid` `adminhelpid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `adminlog` CHANGE `adminlogid` `adminlogid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `adminmessage` CHANGE `adminmessageid` `adminmessageid` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `announcement` CHANGE `announcementid` `announcementid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `attachment` CHANGE `attachmentid` `attachmentid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `attachmentpermission` CHANGE `attachmentpermissionid` `attachmentpermissionid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `avatar` CHANGE `avatarid` `avatarid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `bbcode` CHANGE `bbcodeid` `bbcodeid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `calendar` CHANGE `calendarid` `calendarid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `calendarcustomfield` CHANGE `calendarcustomfieldid` `calendarcustomfieldid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `calendarmoderator` CHANGE `calendarmoderatorid` `calendarmoderatorid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `calendarpermission` CHANGE `calendarpermissionid` `calendarpermissionid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `cron` CHANGE `cronid` `cronid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `cronlog` CHANGE `cronlogid` `cronlogid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `event` CHANGE `eventid` `eventid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `forum` CHANGE `forumid` `forumid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `forumpermission` CHANGE `forumpermissionid` `forumpermissionid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `groupmessage` CHANGE `gmid` `gmid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `holiday` CHANGE `holidayid` `holidayid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `icon` CHANGE `iconid` `iconid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `infraction` CHANGE `infractionid` `infractionid` INT ( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `infractionban` CHANGE `infractionbanid` `infractionbanid` INT ( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `infractiongroup` CHANGE `infractiongroupid` `infractiongroupid` INT ( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `infractionlevel` CHANGE `infractionlevelid` `infractionlevelid` INT ( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `imagecategory` CHANGE `imagecategoryid` `imagecategoryid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `language` CHANGE `languageid` `languageid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `mailqueue` CHANGE `mailqueueid` `mailqueueid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `moderator` CHANGE `moderatorid` `moderatorid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `moderatorlog` CHANGE `moderatorlogid` `moderatorlogid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `paymentapi` CHANGE `paymentapiid` `paymentapiid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `paymentinfo` CHANGE `paymentinfoid` `paymentinfoid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `paymenttransaction` CHANGE `paymenttransactionid` `paymenttransactionid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `phrase` CHANGE `phraseid` `phraseid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `plugin` CHANGE `pluginid` `pluginid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `picture` CHANGE `pictureid` `pictureid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `picturecomment` CHANGE `commentid` `commentid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `pm` CHANGE `pmid` `pmid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `pmtext` CHANGE `pmtextid` `pmtextid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `poll` CHANGE `pollid` `pollid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `pollvote` CHANGE `pollvoteid` `pollvoteid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `post` CHANGE `postid` `postid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `postedithistory` CHANGE `postedithistoryid` `postedithistoryid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `productcode` CHANGE `productcodeid` `productcodeid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `productdependency` CHANGE `productdependencyid` `productdependencyid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `profilefield` CHANGE `profilefieldid` `profilefieldid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `ranks` CHANGE `rankid` `rankid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `reminder` CHANGE `reminderid` `reminderid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `reputation` CHANGE `reputationid` `reputationid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `reputationlevel` CHANGE `reputationlevelid` `reputationlevelid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `rssfeed` CHANGE `rssfeedid` `rssfeedid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `search` CHANGE `searchid` `searchid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `smilie` CHANGE `smilieid` `smilieid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `style` CHANGE `styleid` `styleid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `subscribeevent` CHANGE `subscribeeventid` `subscribeeventid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `subscribeforum` CHANGE `subscribeforumid` `subscribeforumid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `subscribethread` CHANGE `subscribethreadid` `subscribethreadid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `subscription` CHANGE `subscriptionid` `subscriptionid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `subscriptionlog` CHANGE `subscriptionlogid` `subscriptionlogid` MEDIUMINT( 8 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `subscriptionpermission` CHANGE `subscriptionpermissionid` `subscriptionpermissionid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `template` CHANGE `templateid` `templateid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `templatehistory` CHANGE `templatehistoryid` `templatehistoryid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `thread` CHANGE `threadid` `threadid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `threadrate` CHANGE `threadrateid` `threadrateid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `upgradelog` CHANGE `upgradelogid` `upgradelogid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `user` CHANGE `userid` `userid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `useractivation` CHANGE `useractivationid` `useractivationid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `userchangelog` CHANGE `changeid` `changeid` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `usergroup` CHANGE `usergroupid` `usergroupid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `usergroupleader` CHANGE `usergroupleaderid` `usergroupleaderid` SMALLINT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `usergrouprequest` CHANGE `usergrouprequestid` `usergrouprequestid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `usernote` CHANGE `usernoteid` `usernoteid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `usertitle` CHANGE `usertitleid` `usertitleid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `userpromotion` CHANGE `userpromotionid` `userpromotionid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT; ALTER TABLE `word` CHANGE `wordid` `wordid` INT( 10 ) UNSIGNED NOT NULL AUTO_INCREMENT;