You need to share more words with us. As https://proconnect.intuit.com/community/individual/help/diagnostic-reference-ref-frequently-asked-qu... points out search with the number. If you do that you won't find anything. Look at #3 in the link you may find you can just ignore this one.

The full diagnostic is"

Per Maine Tax Alert published January 2020: Generally, the federal changes under the Act first appy to tax years beginning on or after January 1, 2019; however, the Legislature must also consider issues relating to certain retroactive changes under the Act that are applicable to tax years beginning on or after January 1, 2018.  Examples include the exclusion from gross income of discharge of qualified principle residence indebtedness and, for purpose of itemized deductions, the treatment of mortgage insurance premiums as qualified residence interest.  Further guidance will be available once conformity issues have been determined. MRS recommends waiting to file amended 2018 returns until the Governor's proposal is acted upon by the Legislature.  If the Legislature does not enact legislation conforming to those provisions, Maine Revenue Services will inform taxpayers of those tax items and what will need to do to correctly file their original or amended tax returns or to make changes to 2020 Maine estimated tax and withholding. Adjustments and modifications can be made on Maine Schedule 1, other additions/subtractions.  For more information visit https://www.maine.gov/revenue/publications/alerts/index.htm (ref. #53561).

You just ignore the diagnostic if it doesn't apply to you. Not all diagnostics can be cleared, and many "critical" diagnostics don't interfere with e-filing.