Is this about bitlocker for business accounts or personal accounts?
There has been issue with personal account loading bitlocker page,
This issue is server-side related, and it is temporary and intermittent.
A potential workaround is, sign into your account https://account.live.com, then click on "change password" on the upper right. Make sure you replace it with a stronger/longer password. Then try to access the bitlocker page again. This seems to work for some users.
The issue shouldn't affect business accounts though.