The 'gs.addErrorMessage()' function in Business Rules on the 'sys_attachment' table does not work correctly when uploading attachments with the 'Choose file' button.
Steps to Reproduce
1. Log in as administrator.
2. Import the attached XML file 'sys_script_44ab381bdb3ca7008d92e5951b9619c6.xml' which shows an error message on the form while uploading attachments.
3. Navigate to 'incident.list'.
4. Open an incident Record.
5. Click the 'Manage Attachments' button on the form header.
6. Drag an attachment and drop it on the pop-up attachments window.
7. The attachment is uploaded and the error message is showing on the form.
8. Close the error message.
9. Click on the 'Choose Files' button on the pop-up window.
10. Select a file on the file selection window and click 'open' to upload.
11. Observe the attachment gets uploaded successfully, but the expected error message is not showing on the form.
12. Optionally check the system logs and verify the Business Rule was executed.
This is expected behaviour. Session messages are not shown unless the page gets refreshed, which in this case does not happen.
Related Problem: PRB1309675