After blogging about fixing one report problem, that was using the packed Query, at http://axfaq.blogspot.ro/2015/08/ssrs-report-using-old-query-definition.html (SSRS report using the old Query definition) I realized that I missed out to mention a general development / testing cycle rule.
We are all aware that during the initial phase of the development some objects will tend to change heavily between iterations. This can lead to usage errors either on the developers machine, as well as on the test machines. Since we are using heavily automated scripts for building and deploying machines, the following advice is easier to implement since you can include it in your scripts. However, even if you do not use scripts, a cleanup from time to time I believe is a good idea.
With this context in place, one piece of advice (that I tend to forget from time to time on my development machine, at least) is clearing out the Usage data. This will remove all the saved metadata that might interfere with your testing.
Of course, I'm sure most of you know, but for the newcomers, you can do that either from your Tools -> Options -> Usage data -> Reset (this will remove the data only for the current user) or if you like to do it for all the users and enjoy using the SSMS as I do, just execute a TRUNCATE TABLE SYSLASTVALUE. Of course, you can choose what type of data to reset, just like in my initial case, I had some issues with the reports, you can just delete the reports data.
As always, please be careful when doing this, as someone might be using that information you're just deleting.