• GitLens Version: 10.2.1
• VSCode Version: 1.45.1
• OS Version: Ubuntu 20.04

Steps to Reproduce:

1. Create git repository with submodule(s), create a commit involving a submodule.
2. In branch history locate and expand that commit. Click on the submodule.

Result:
Error "Unable to open '<submodule> <hash> ... "
Looks like VSCode is trying to compare submodule directory as if it were a file.

Expected:
Display submodule hash diff, the way VSCode's git integration does this:

diff --git a/submodule b/submodule
--- a/submodule
+++ b/submodule
@@ -1 +1 @@
-Subproject commit b1601e42183b31af1afc6ceedd4cb9b3efb27f0d
+Subproject commit 388ba770105a27e5589e55ad56dcf9dbd407d134