The add form just worked for me to access form 8949. Did you type in form 8949 after clicking on the Open Form button?

Do you have the latest program updates? Click on Online at the top of the screen and Check for updates. 

I did make sure I had all updates, but I get the same experience as posted above. The (Add Form) button is blue, but does nothing when clicked.  My challenge is the IRS person I'm working with on my amended return says I must have the 8949. I can fill it out manually, but it seems odd it isn't there based on the correct import of cap gains from my brokerage firm.  The 1099B is listed correctly, but does't show the individual long term cap gains sales which IRS is requiring.

Again ... to populate the 8949 you must enter the sales in the interview ... it is not a form you should populate yourself unless you get blank forms from the IRS ... let the program do the work for you.

If your downloaded program is updated and the 8949 is not being populated  or is not showing in the return PDF then  do a full uninstall of the program then reinstall it as it may have become corrupted.

Or maybe instead I'll just find some tax software that actually works correctly.

Certain forms are generated forms. You can't access them directly.
There's nothing unusual about that.

You can open Form 8949 for examination or printing but you can't modify it.

I already have my 8949 form filled out via bitcoin.tax software, just need to add to to my finished taxes in TurboTax, but that's not possible. So why would I pay $140 to file when I had to fill everything manually anyway?

My W2 didn't even import correctly. TurboTax providing W2 plus one other form and nothing is working correctly. Total joke this year.