Evaluating Lambda expressions in debugger (watch window) is not supported yet.
Theres an open feature request for it.
For debugging your problem you should assign the result of the lambda expression to a dedicated variable and use that in following statements.
var entity = entityvDetails.Where(e => e.sad_id == item.sad_id).FirstOrDefault();
Update 08/2014:
Microsoft posted an update on the feature request announcing that they started to work on it:
So here’s where we stand.
- 1) We want this to work as much as you do. It’s not under review – it’s in progress.
- 2) We figured out how to make it work; it simply requires rewriting everything.
- 3) We’re rewriting everything.
- 4) Rewriting everything takes a lot of time and a lot of testing.
Update 11/2014:
Microsoft finally implemented it with some limitations in VS2015. Read here.