We are looking in to the issue.
Please send a screenshot so that we can check further...
In the meantime you can access your sandbox using direct Innovation Studio url - https://developerxxxx.innovate.bmc.com/innovationstudio/index.html
Please substitute your sandbox number instead of xxxx.
Not able to see it for me. can you please turn on developer tools in the browser and check what is being loaded in white box and is there any error in the loading process.
first of all the issue only occurs with firefox. I run the developer tools, but there is no error and after few seconds the page will be reloaded automatically.
Do you still have the problem? I tried on Firefox and did not see the box.
No, now I cannot reproduce it anymore.