MS CRM 4.0 prepare for diagnostics and debugging

I am working on project where we are making quite a few integrations to the CRM. And yesterday I got into a trouble.

A colleague of mine has created on his development machine few new entities. I exported the customizations and then imported them in my CRM development, and here is started. One of the entities was not showing the Icon, I couldn't open the new form, I couldn't do anything with that entity. I have tried to delete the customization and again nobody. Like a friend said "A BIIIG PROBLEM".

Here is how I have solved it.

1. Turned on the development error in the web.config.
   

   <appSettings>
   

   <add key="DevErrors" value="On"/>
   

2. Turned on the tracing http://support.microsoft.com/kb/907490
   
3. Then it seems that I had to recreate two attributes that were added and then deleted, but somehow the CRM new about them even when the entities were exported.
   

So good luck to you too when you are looking for errors with the CRM.