I'm trying to complete the challenge in "Create Transaction Security Policies" unit in the Transaction Security Module. I'm following the directions explicitly, but for some reason, when I create the "New Custom Transaction Security Policy", and I choose the only user available in the drop-down (which is me with Sys Admin rights) for "Execute policy as" property, I keep getting the error: "Specify a valid execution user". Again, this user is a sysadmin and it won't accept it as a valid execution user. Not sure why a user with sysadmin rights would not be considered a valid execution user. I've tried creating new playground instances, but still I get the same error. I'm dead in the water at this point and can't finish this trail! Please help!

I'm trying to complete the challenge in "Create Transaction Security Policies" unit in the Transaction Security Module. I'm following the directions explicitly, but for some reason, when I create the "New Custom Transaction Security Policy", and I choose the only user available in the drop-down (which is me with Sys Admin rights) for "Execute policy as" property, I keep getting the error: "Specify a valid execution user". Again, this user is a sysadmin and it won't accept it as a valid execution user. Not sure why a user with sysadmin rights would not be considered a valid execution user. I've tried creating new playground instances, but still I get the same error. I'm dead in the water at this point and can't finish this trail! Please help!