When a record producer or a catalog item is opened in Service Portal, the user gets a null pointer exception(java.lang.NullPointerException) and the item does not open.
Any supported version
This is caused when there is a reference variable in the catalog item that references a table which does not exist in the instance. To easily identify this, under 'Type Specifications' tab in the variable record, the affected variable does not have the Table Name and it only shows the table name.
In order to resolve the issue, create the table that is referenced in the variable.
This is usually caused in the cases when the catalog items/record producers are brought over from other instance and the referenced table missing in the target instance.