You can experience some problems if you set a value on the ‘CaptionClass’ system tables on NAV 2009 or NAV 2009 SP1. This can also happen if you had already a value on one of the ‘CaptionClass’ system tables on previous versions, and you upgrade to either NAV 2009 or NAV 2009 SP1.
Problems can appear any time the engine is trying to recompile the system tables, for example, when importing fob files, when re-compiling, or when re-enabling the ‘Enable for Microsoft Dynamics NAV Server’.
The problem can be prevented if you either: Remove the offending CaptionClass (on the corresponding System Table) or if you Disable the ‘Enable for Microsoft Dynamics NAV Server’ (this will prevent you from using the three tier architecture).
We have identified this problem and should be solved in the Microsoft Knowledge Base 977121.