At Compilation time, in the Designer, when an error happens, there is no enough information regarding the error, the source and the step where the error happened. Provided error messages are generic and there is no clue about the issue.

For instance, if the process contains big number of activities and lets say we make some changes in 10 or more activities/scripts at the same time. When an error happens, the only way to find out where the error is to check each activity one by one in order to finally find out the source of the error. See attached compilation_error.png screen shot as an example.