I did an additional test. This time, when importing my data, I imported all except the 1099-B data. 1099-B contains stock trades. After the import, the 'File' menu works as it should.
I did one last test. I went back to import the 1099-B data I had excluded previously. The 'File' menu problem appears after the 1099-B import.
As others have noted, the issue appears to be related to import of brokerage trades. It may be the result of numerous trade transactions.
