Repro steps

let x (enumerator: IEnumerator<'t>) = ()

Use the suggested code fix for IEnumerator.

Expected behavior

Code fix suggests to open System.Collections.Generic.

Actual behavior

Code fix suggests to open System.Collections, which only contains the non-generic IEnumerator.

Known workarounds

None.

Related information

VS 17.8.0 Preview 3.0