Hi Sebastian, my apologies for not replying earlier.

I've tried removing the email validation and a number of other long settings, but with no success.

I'll log the issue as suggested.

Thank you very much for your help.

Kind Regards,

Andrew

I suspect that the error is occurring when the Site Settings page binds data to the Folders combo box (DnnComboBox control) for the first (Site Logo) of the three DnnFilePickerUploader controls used in the Appearance section of Basic Settings on sites which have created a very large number of portal folders and sub folders. That would especially be the case for those receiving a large number of bogus user registrations where one or more folders would have been created for each newly registered user.

As part of cleaning up the bogus registrations, it is important to either make use of the Remove Deleted Users command in the site's User Management or a third-party tool which will physically remove the user folders that have been created as well as removing the user registration from the database.

The DnnFilePickerUploader control in v 7.2.x makes use of the Telerik RadComboBox for its two DnnComboBox controls. Since the serialization error noted in the stack trace is actually occurring in the Telerik RadComboBox control, it is possible that this error will not occur following an upgrade to DNN v 7.3.x in which the DnnComboBox control was rewritten to remove the Telerik dependency. While upgrading would be recommended, I would suggest clearing out the bogus user folders before an upgrade or doing a test upgrade on a clone of the site first.