3782374 - Cannot save new validation rule and view script in app F4406 - SAP S/4HANA Cloud Public edition

It is not possible to save a new validation rule in the F4406 app or when the Save button is pressed, nothing happens.

It is not possible to view script. 

"Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental."

SAP S/4HANA Cloud Public Edition

F4406, manage substitution and validation rules, validation rule not saving, save button unresponsive, cannot view script, operator not equal to, is not empty, value field blank, s/4hana cloud public edition, data validation, business rule configuration, validation operator, rule script not opening , KBA , FI-SL-VSR-2CL , Validation, Substitution and Rules (Public Cloud) , Problem