When you try to sign in with your Office 365 calendar, the OAuth authorization flow may return an error "Sorry, but we’re having trouble signing you in. We received a bad request", with details: “AADSTS90093: Does not have access to consent.”
“AADSTS90093: Does not have access to consent” error you are receiving indicates that your IT department turned off the ability to authorize 3rd party apps to connect to your Office 365 account.
FreeBusy (and any other 3rd party app) is prevented from accessing any data whether calendar, contacts, or email. It's unfortunate they made this decision because Office 365 has an entire system of granular permissions so someone like yourself gets control over which apps you authorize and which specific data the apps can access.
There are two ways you can move forward from here:
- You can authorize FreeBusy to connect to your Office 365 account using your Exchange Online (aka Outlook Web App aka OWA) username and password. This is an alternate way to allow connectivity to your calendar and it requires that you input your password on FreeBusy. Learn more about how we protect your Exchange Online password.
To do so, go back to sign up and provide your Office 365 email address. After FreeBusy detects Office 365 as your calendar provider and shows you the Office 365 sign in prompt, click on Choose your calendar and manually select Exchange instead of Office 365 as your calendar provider. When FreeBusy asks you for the OWA username enter your email, when it asks for your password enter your password, and for the OWA address enter https://outlook.office365.com.
- Alternatively, you can contact someone at your IT department to request a policy exception (for example they can whitelist FreeBusy). We're glad to join the thread and explain what we do, to assuage any concerns they may have. Note that Level 1 support (i.e. frontline helpdesk) won't be able to help you and might not even know what to do. You should ask them to escalate your request to Level 2 support who are the people deciding and implementing the various IT security policies.