How to get display a warning in case a new task is received
On occasions the creation of a promotion request can produce an error due to the checks build in there. The user does get an error task in this case but if he does not verify his homepage he is under the impression that the promotion request went through and waits for approval. It should be good if he would get a pop-up box informing him that an error task exists for the just created pr.
Re: How to get display a warning in case a new task is received
We have added a number of validation checks into the promotion wizard (before PN is create) but this is a fairly heavy customization.
You could handle the errors in workflow with better email notification, if you consider that helpful. Of course you are still responding to a problem, rather than stopping it happening in the first place.
It is also a good idea to make sure your permission model does not allow standard users to checkout while the promotion objects are in the target state or the lock state.