I keep trying to download my 2019 return through the app and it just keeps coming up with an error message each time. Any ideas?

We cannot see your return or account here, as this is a public forum. Please paste in the error message you are receiving so that we may better assist. 

Do you get the error message when you try to download it or when you try to open it after it downloads?

What file are you trying download?  Is it a .tax or .pdf or .txt file?  If it downloads as a .txt file, try changing the .txt to .pdf or use a different browser to download it.  It doesn't like Microsoft Edge so use something else like Chrome or Firefox.

How to get a copy after filing

https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-get-a-copy-of-a-return-i-filed-this-year-in-turbotax-online/00/25932