The Installation Guide for Web Help Desk 12.5.2 (the latest release) states that the following MS SQL versions are supported: SQL Server 2008 R2 SP3, SQL Server 2012 SP2 or SQL Server 2014.
I am led to believe that if SQL Server 2016 is supported, then SQL Server 2008 R2 will be dropped.
Please note that it doesn't mean that any version unspecified won't work with Web Help Desk, it just means they aren't tested or supported versions that the product currently uses.
As usual, anything that is not tested or unsupported, will have limited support from the SolarWinds team, although they will try to assist as best as they can.
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