Hi PAOLA MONTENEGRO,
Thank you for reaching out to us on the Microsoft Q&A forum.
We are sorry to hear that you are experiencing issues in accessing the sandbox.
This can happen when our automated system detects potential misuse of the platform, for example: banned code, unexpected outside the lab activities. Once banned, all Microsoft learn sandbox activations will be blocked. Use the appeal button to submit a review request. Our backend team will verify the lab activity and unblock the sandbox within 24-36 hours if the appeal is successful.
Till then once try to follow the troubleshooting steps as mentioned below for the issue:
Step 1: Sign-out from all the tabs in the current browser and clear the cache files and try login again with your learn id credentials.
Step 2: Sign-out from current browser login and try to login from an incognito window/in-private window.
Step 3: Switch to a different browser and try login again.
Step 4: Login with a new personal email account into the learn path in a completely new browser and check.
If the information is helpful, please accept the answer by clicking the "Upvote" and "Accept Answer" on the post.
If you are still running into issues, kindly attach the screenshots of the error you are getting. We will glad to assist you.Thank you.