ConcurrenctionException can not be Catched

[sbgmk]

I insert some Config into my Ravendb and use optimistic concurrency. If i insert the same Document the second time with the same Name the ConcurrencyException is getting Thrown. Thats the intended behaviour. But even if i Catch the ConcurrencyException i got the same Exception with the RavenDB error in the middleware again. This behaviour is unexpected.
My question is: Where is the second Exception being thrown from and how can i Catch this or prevent it.

We use ASP.Net 6 and the below code gets called in our API Controller.

      try
       {
            var workConf= new WorkConf  {  Name = dto.Name  };

            await _session.StoreAsync(workConf);
            await _session.StoreAsync(new Reserved{ ReservedFor = workConf.Id }, "Name/" + workConf.Name);
            await _session.SaveChangesAsync();

            var workConfRef = new WorkConfReference(id: workConf.Id, name: workConf.Name);
            return DomainResult.Success(workConfRef);
        }
        catch (ConcurrencyException e)
        {
            return DomainResult.Conflict<WorkConfReference>(_localizer["Item_Not_Unique"].Value);
        }

[ayende]

Are you using the same session again? Once you got ConcurrencyExcpetion you should create a new session.

If you are calling SaveChangesAsync in the middleware, it does the same operation, and it will fail again.

You can call session.Advanced.Clear() to reset the entire state, so the middleware call with be a noop.

[sbgmk]

Thank you for your Awnser. session.Advanced.Clear() solved the Problem for me.