I am trying to download a form 8949 from Apex Clearing Corp and I am unable to complete the download

You don't download 8949.  You fill it out as part of your tax return.  You should have a 1099B for investment sales.

Thanks...I was hoping to not have to physically mail the 8949 after I e-file as it is 99 pages of trades and summaries.

@bfmurphy75

TTX Online probably cannot handle that many trades:

Read this:
<a rel="nofollow" target="_blank" href="https://ttlc.intuit.com/questions/1899287-how-many-stock-transactions-can-turbotax-online-handle">https://ttlc.intuit.com/questions/1899287-how-many-stock-transactions-can-turbotax-online-handle</a>

And this too, if there are still too many for the Desktop software.  IF you are going to be making thousands of trades, you may need to learn how to use the "summarization" procedure (Step 1 and Step 2 in the following):

<a rel="nofollow" target="_blank" href="https://ttlc.intuit.com/questions/2963870-how-do-i-enter-more-than-500-stock-transactions-in-turbotax-online">https://ttlc.intuit.com/questions/2963870-how-do-i-enter-more-than-500-stock-transactions-in-turbotax-online</a>

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In either case, you will need to review what downloads meticulously in any case...

Thanks for the response....Steps 1 & 2 above are what I have done.

The instructions are out of date for 2016 and the FAQ needs to be updated. If all your trades are covered transactions with no adjustments i.e. no wash sales (see consolidated 1099-B) then neither of those steps is necessary.