When error or warning messages occur they are presented to a user after double clicking on the row in a dialog box with a whole bunch of text. The problem with is firstly, that stack traces and raw type java error messages are shown to the user which may be confusing to some. Although it would be best to keep such error messages to assist in resolving issues, it would be better if items other than the user friendly error text where hidden by default or made less prominent.
This situation is worsened when there are multiple messages as the messages are just added as text one after the other. Thus with large stack traces multiple errors can be separated by quite a bit. It would be nicer from a user perspective to have the resultant errors and warnings separated and summarised (with details still available). The summary should at least show the number of errors and warnings. The solution might be to have the short warning messages in a table with the details (such as stack traces) available after clicking on each item. Alternatively having the items all as expandable text, starting out all collapsed (with just the short message showing).
Note that the solution should also take into account the need to show, possible multiple, warning messages on successful normalisation/conversion (see rfe-3396037)