Hi Lev Rosenblit,
The code sample you provided below is exactly how you would access product custom fields. I want to thank you for sharing the sample with the rest of the community.
Regarding the errors that you ran into -
1)"Unknown DB mapping" error is a known issue with Product Types which we have logged in our PITS
2) I was not able to reproduce your issue completely. I noticed that the database tables of product types still exist although the product type is deleted but as soon as I deleted the product type the links for create a.. did go away. Please provide me with more information to debug your issue.
the Telerik team
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