Error - Method not found '!0[] System.Array.Empty()'

We’re running SCCM v1906, Console version 5.1906.1096.1600 and RCT version 4.0.7171.38436.
We get this error, Error - Method not found ‘!!0[] System.Array.Empty()’. when trying to use any of the RCT functions.
The SCCM console crashes if you click OK.
I tried uninstalling the RCTs, deleting the Recast Software folder and reinstalling.
Has anyone seen this before?

Can you check to make sure .Net 4.6.1 is installed? There’s a bug in our installer where that prereq check doesn’t happen currently.

That was it. The box the console and RCTs are installed on had an old version of .Net. I installed a copy of 4.7.2 and the tools are working. Thanks for the quick response.