I'm setting up a system in 8.5 2018-10-04. When saving a new Contact record, and the e-mail address is blank, the message "May not be blank" appears, and the cursor takes you to the e-mail field. If a contact has been imported without an e-mail address, when you try to update the contact and save it, the same message appears but the cursor does not take you to the e-mail field.
I've had a look through all the record checks to do with CUVc and cannot find anywhere that requires an e-mail address. I've added a trace at the beginning of CUVcRecordCheck, and the trace does not appear, so this would indicate that either some HAL or C code is running before CUVcRecordCheck is run.
I have tried this in sample data using the same version and HAL, but it does not ask for the e-mail address to be non-blank. Does anyone have any ideas on this one?