When the dealer faces error message while submitting CST return, he/she should first open their CST Annexure XML file with Mozilla Firefox browser in computer.

1. Then they should check for the error notification of the Firefox browser regarding the XML file.
2. The Mozilla will automatically find out the erroneous portion of the XML file and show the user the approximate line number of that particular XML file where those special/malformed characters exist.
3. The user should install Notepad ++ Editor in their computer. (Link for free download: https://notepad-plus-plus.org/download/).
4. When the Annexure file is opened with Notepad++, he/she can easily find out the erroneous portion with the line no. which was shown by Mozilla browser.
5. Then dealer should remove those entries from Annexure XML and save it.
6. He should now try to re-upload the CST again.
7. Problem should be solved by this process.