Data type STR15 does not exist in the dictionary. Parameter name: datatypeName

I received the following error whe launching Dynamics GP 2010 R2 SP3 for the first time after upgrading from Dynamics GP 10 SP 5

".DLL: Data type STR15 does not exist  in the dictionary.  Parameter name: datatypeName"

It turns out my non-upgraded forms and reports were causing this issue. 

1. Remove FORMS.DIC and REPORTS.DIC not yet upgraded
2. Launch Dynamics GP 2010 and register etc
3. Upgrade Forms and reports using Dynamics Uttilites

or
1. Upgrade Forms and reports using Dynamics Uttilites
2. Launch Dynamics GP 2010 and register etc