Worker Phone - Unable to update the Area Code as #NULL

Summary:

We are correcting the phone numbers of the employee using SHDL. We are concatenating the existing Area Code and phone number and loading it under Phone Number. The Area Code has to be made blank. However when we try to load using SHDL with #NULL against Area Code, we get an error. (If we make Area Code as blank, the data is loaded successfully. After the successful load, the area code is still having old values which is as expected)

Content (required):

Please suggest how to fix this.

Version (include the version you are using, if applicable):

23B

Code Snippet (add any code snippets that support your topic, if applicable):