The "Bad conversion" error in MIP SDK when labeling emails may occur due to issues with the email's format or attachments. One possible solution is to check the email's format and attachments to ensure they are compatible with MIP SDK. Additionally, you can try using the MIP SDK diagnostic tool to troubleshoot the issue further.
Here is a link to the MIP SDK FAQs and issues page, which may provide additional information on this error:
References: