B column on 1095A has zeros. Alerted by system there can't be a 0 in the column and find out the second lowest cost for silver plan for taxes. Correct? AccessHealthCT

Take the zero out and leave those spaces blank.

If the SLCSP is missing or incorrect in column B - Part III of your form 1095-A, you should use this tax tool to find it and enter it on your tax return. Failure to do so will result in a wrong calculation of your premium tax credit.

cant leave it blank doesn't work

You must have Column B information entered for the required Form 8962 to generate.  Click on "click here" if Column B on your 1095-A reflects $0 on the Let's get the info from your 1095-A form page.  A pop-up window will provide further instructions.  See image below.

You can use the "Healthcare.gov/tax-tool"  or call your marketplace insurer to get the data for Column B that you need. Column C will accept zeros but not blanks.