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====== Restoring the previously installed version of eBiss ======

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 ({{:images:sign_warning.png?nolink|}}) 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. 

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**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.
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Enter the required version in the database, in the **AssemblySchemaVersion** table, for the entry where "AssemblyName" = "eBiss.Data", e.g.:
<code sql>
  UPDATE AssemblySchemaVersion SET Version='<the version number>' WHERE AssemblyName = 'eBiss.Data'
</code>
Replace <the version number> with the required version.
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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:
  - update to the reset version or a newer one, and
  - manually enter the **DB schema version** noted above into the database, as the database schema is already at this version.