Why can't I download into QuickBooks desktop anymore

Which version of QB Desktop are you using?  If you are using QBDT 2018 or earlier, you have reached the end-of-life and the Bank Feed will not work anymore.  (QBDT 2019 will end in May this year.)

The common issues with Bank Feeds are issues at the Bank end the QBs side has been corrupted.  So if you haven't recently logged directly into your Bank's Online Acct, I'd do that just to make sure there are no issues with your Account.  Many banks are adding additional Security Protocols, so it is possible you missed a letter that was telling you they were going into place.  It never hurts to call the bank too and confirm they are not having any issues with QBs. 

In QBs you can try resetting your Online Services.  Go to the Chart of Accounts and then to your Bank Acct and Edit the Account.  Click on the Bank Feed Settings tab and select Deactivate All Online Services.  Then Save & Close and exit out of everything. 

Close QBs, reopen QBs and then go do the Activate Online Services again.  This will often clear up issues.

Also, if you haven't updated your version of QBs in a while, I'd do that too.  Go to Help, then Update QuickBooks Desktop (not Upgrade...).

Good morning, @cazuelapayroll.

Thanks for taking the time to reach out to the QuickBooks Community and sharing your concerns.

Would you mind clarifying what you're trying to download into QuickBooks Desktop? Would this be your QuickBooks Online data? Or your Payroll data? Also, if you don't mind, could you share what is happening when trying to download? If you're getting an error, could you share a screenshot? 

Knowing as many details as possible will better assist me with solving this concern for you. I'll be sure to keep an eye out for your reply and look forward to chatting with you soon. Take care!