I have a solution that has started throwing null exceptions when trying to save users:
System.NullReferenceException: Object reference not set to an instance of an object.
at Dynamicweb.Security.UserManagement.UserRepository.FillRow(DataRow row, User user)
at Dynamicweb.Security.UserManagement.UserRepository.SaveUser(User user)
at Dynamicweb.UserManagement.Frontend.Frontend.SaveForm(ParagraphSettings settings)
at Dynamicweb.Frontend.Content.GetModuleOutput(Paragraph paragraph, PageView pageview)
The origin of the save does not seem to matter, as it happens when creating normal users, when creating users from an external login and when saving users in custom code. According to visual studio, the null exception is thrown in the foreach loop that goes through users.CustomFieldValues in UserRepository.FillRow(DataRow row, User user), but I'm not sure how accurate that is.
Is this a known bug that has been fixed in a future version? the solution is on DW 9.13.3 and Dynamicweb.UserManagement 3.0.7