Thank you for your feedback!
When using Office365 account, the only specific thning is that the e-mail is used also as username.
Could you, please check what you are using as username- the part before '@' or the whole e-mail value?
Thank you for helping to make Tasks better!
All the best,
the Telerik team
Explore the entire Telerik portfolio by downloading the Ultimate Collection trial package. Get it now >>