I discovered an interesting ‘gotcha’ with managed solutions and reports the other day. We had deployed a managed solution that contained a few reports, and then later we decided that one of the reports was no longer necessary. Instead of leaving the solution cluttered with a report that is no longer used, we proceeded to delete it from the managed solution. However when we tried to import the updated solution as managed into our QA environment (that had the older version of the solution with the extra report), I received the following error:
Managed solution cannot update reports which are not present in solution package. Report 81E46F90-FDA8-4103-866A-3142B8B34E08 is not part of current solution
The error makes sense that CRM cannot update a report which in not present in the solution, but I found it surprising that it would even attempt to! Unfortunately this error prevented us from cleaning up the solution a little bit but there is a workaround. You can edit the report and change the name to denote that it isn’t used anymore. Also null the values in Categorization, most importantly the Display In field so that even though the Organization will continue to have the old report, it will not be displayed anywhere.