Symptoms of App and Stuido if there is a invalid field in the List AppletThe invalid field means a field actually doesn't defined in the table but it is used in the List Applet created based on that table. For example, a customized field is created on the incident table and it is used in the incident List Applet List. Then it is deleted form the table but not removed from the List Applet. Below are different symptoms caused by the invalid field. The invalid field is in the Data Item Condition App: The List Applet will be missing. Studio: The invalid field will not be loaded to the Data Item Condition. Need to check via showing XML. The invalid field is in the List Item View or Form Screen Header Item View App: The invalid field will not be showing on the List View and Form Screen Header Item View. Studio: The selected fields will be all empty. The invalid field is in the Screen fields App: The invalid field will not be showing on the Form Screen. Studio: The List Applet cannot be opened in Studio. The following error message pops up. "java.lang.NullPointerException Check logs for error trace or enable glide.rest.debug property to verify REST request processing" The invalid field is in the Field Function instance App: The iField Function doesn't work. Studio: The List Applet cannot be opened in Studio. The following error message pops up. "java.lang.NullPointerException Check logs for error trace or enable glide.rest.debug property to verify REST request processing"