I sold stocks, but did not receive a 1099-B. I clicked that I did not receive a 1099B, yet the program still asks me to input information from the 1099-B.

[josianator]

You will probably need to request the 1099B from your broker.  For example with TDAmeritrade these documents are available online upon request (it seems like they sometimes send a paper copy and sometimes not), although as a 1099 consolidated form (which is confusing because it is not the same format as 1099B).