Check if Windows
Defender feature Ransomware protection is enabled.
If so, configure it to add Quicken as an "allowed app" without
turning off Ransomware protection. Perform the last step in:https://community.quicken.com/discussion/7857675/faq-windows-defender-controlled-folder-access
Are you getting
"Oops, something went wrong"?
Have you recently enabled a VPN? If so, this might be the problem. Try turning
the VPN off and see if that helps.
Is there a corporate
or otherwise external firewall getting in the way? Contact the IT people
maintaining the firewall and ask for permission. Quicken needs to be able to
establish outbound internet connections for the program to work.