Forms view 1099-B has red exclamation point, says sales information is missing (data was imported). No field is highlighted, everything looks OK. How to fix it?

It sounds like there may have been an issue with the imported data for this transaction. I recommend going into the return itself to check for issues. You may even consider deleting this particular transaction and reentering it manually. Here's how:

1. Open (continue) your return if it isn't already open.
2. In TurboTax, search for 1099-B and then select the Jump to link in the search results.

Called help line. Learned you can only edit forms in step-by-step. Once I went there it clearly showed which items "needed more info", I was able to edit them and Red exclamation point went away in Forms view.