If you are using Kaseya v6.2, v6.3 or v6.5 before you attempt to upgrade to v8 of VSA please uninstall any existing Addins.
Note: All Addins prior to v4.3 are incompatible with Kaseya v7 or newer.
Next you will need to clear the SQL ksubscribers database. Please following this article "How to remove AuthAnvil database schema from Kaseya when it's not needed' - https://help.scorpionsoft.com/entries/74392436
Once you have the DB cleared please contact support for the v4.3 addin that is compatible.
If you already have the addins
If you have any questions or need some help, we would be happy to assist. Open a case at kaseya.zendesk.com .