When you try to sign in to Microsoft To Do with a Work Account and see the error message:
"Sorry, there's an issue signing you in right now. Please try again and contact support if the problem persists.", alongside an error code, such as:
or something similar, please try the following:
go to Windows Settings > Update & Security > Check for Windows Updates
try rebooting the PC or Mobile device
After that, try to sign in to Microsoft To Do again. In most cases this should help solve the problem. In case the error keeps happening after that, please send us a message here.