That is extremely strange, the first part of the altertable portion of the v8 upgrade utility was supposed to convert the two memory tables (ubbt_ONLINE and ubbt_TOPIC_VIEWS) to a standard MyISAM table from a MEMORY/HEAP table.

The initial fix in ~v7.1 was to make this high resource table exist only in MEMORY so that it wasn't constantly writing to the disk, but now adays this isn't needed as SSD disks are common and the speed improvement isn't really happening anymore. You can read more in the in a support page here.

You have two choices, either convert the table to a MyISAM table in PHPMyAdmin (I believe under operations) or empty the table and leave it as a MEMORY type.

I am a Web Development Contractor, I do not work for UBBCentral. I have provided free User to User Support since the beginning of these support forums.
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