Why is TurboTax telling me I am not eligible for a Lump sum retirement credit when I did not take the credit in a prior year and it was NOT through IRC 403(b) or IRC 457?

To qualify for the lump sum, you must meet these qualifications, according to Lump sum distribution credit:

Line Item Overview: If you take this credit, you cannot take the $50 senior citizen credit on this year's return or on any future return.
To qualify for this credit, all of the following must be true:
 

• Your modified adjusted gross income less exemptions is less than $100,000;
• You were 65 or older during the tax year;
• You must have received a total, lump sum distribution from a qualified pension, retirement or profit-sharing plan; AND
• You have not previously claimed this credit.

Supporting Documentation: Lump sum distribution credit worksheet and 1099R showing "Total Distribution" box checked

An example of a 1099-R and Lump Sum Distribution Worksheet can be found here.

Reference: Retirement Income - Ohio Department of Taxation