I'm trying to upgrade a unit test project to the latest version of FakeXrmEasy 2.1.2 and I'm getting the error below:
'XrmFakedContext' does not cointain a definition for 'ExecutePluginWith' and no accessible extension method 'ExecutePluginWith' accepting a first argument of type 'XrmFakedContext' could be found

This might happen because some methods were moved into dedicated namespaces and so some extra using statements might be necessary.
Please try adding these usings:
Also please check the documentation site with other steps that might be useful. In particular the Quick Guide to migrate in 6 steps is probably an essential resource:
https://dynamicsvalue.github.io/fake-xrm-easy-docs/quickstart/migrating-from-1x/