It is almost always possible to restore the previously installed version of eBiss, unless there have been significant changes. Any such significant change would be explicitly noted in the release notes with a warning () and text stating that it is not possible to restore the previous version of eBiss.

The easiest way to restore the previous eBiss version without losing any data, including log files, is to start the setup from the previous eBiss version.

at the end of the setup, when the title reads “The installation is complete”, select “Start Configuration Wizard”. This will launch the “eBiss 3 Configurator”. In this window, click “Next” until the message appears: “You must not migrate to an older DB version”. Confirm the message; you will now see the DB schema version and the required version at the top of the window. Make a note of both versions; you will need the DB schema version for the next eBiss update.
Enter the required version in the database, in the AssemblySchemaVersion table, for the entry where “AssemblyName” = “eBiss.Data”, e.g.:

  UPDATE AssemblySchemaVersion SET Version='<the version number>' WHERE AssemblyName = 'eBiss.Data'

Replace <the version number> with the required version.
Return to the wizard, click 'Back' once, then click 'Next' n times; the wizard will run through to the end. Once the wizard has finished, it will take a few seconds for the setup to complete, after which you can launch the restored eBiss version.

For the next eBiss installation, please ensure that you:

1. update to the reset version or a newer one, and
2. manually enter the DB schema version noted above into the database, as the database schema is already at this version.