What causes error: "Illegal circular USE: DocExpProcessing" in Lotus Notes?

While working with Lotus Notes, you can receive an error that starts with “Illegal circular USE:”
in several situations such as: copying a design element between database designs , opening or creating database and mail files . This error mainly occurs due to error in mail files, error in LotusScript libraries, database design updates (relative to Notes/Domino templates) or an updated version (relative to custom templates).

Some general scenarios when Lotus Notes user receives the error "Illegal circular USE: " are:

• While working within a database or mail file
• While opening database or mail file
• While creating database or mail file documents
• While purging database or mail file documents in folders
• While opening a Notes mail folder
• While performing the 'Send and File' action in foreign language mail templates
• Other Lotus database operations

Here, I am discussing the specific case Error: "Illegal circular use: ..." when working within a database or mail file. This may lead to improper functioning of Lotus Notes client or Lotus Domino Web Access and can cause troubles when a user tries to open his mail database.

Causes:
This error is caused due to errors in the LotusScript code such as:

• Corrupt script library
• Un updated script libraries

Note: script libraries aren’t up dated, if you enable the "Prohibit design refresh or replace to modify" property for your Lotus Notes.

Before going further to resolve the error, first we must know the way to diagnose the problem so that proper error resolution method can be adopted.

Follow the given steps to diagnose the problem:

To make sure that the database's design elements will be updated whenever refresh or replace occurs, you must ensure that the Refresh/Replace’ property flag or "No Refresh” column (for later Domino Designer clients) isn't checked for database's design elements in Lotus Domino Designer.

1. Check the error message and see what the cited design element is.
2, Open the database using Domino Designer.
3. Go to Shared Code > Script Libraries from the left pane. Check if the library name noted in the error message exists in the script library design elements or not.
4. Ensure whether the "No Refresh" column is checked for the design element or not. Also, see if the "No Refresh" column is checked or not for other database design elements (including Views, Folders, Forms and Subforms etc.)
5. Make sure that prohibit flag is not checked the for the design elements in the source template.

If you have performed all above steps but still facing the same problem then, the error is being caused due to some missing or corrupt database design element. Read my next article to know the ways to resolve Lotus Notes error "Illegal circular USE: DocExpProcessing".