If you're seeing failures when trying to startup a job, workspace or app the best place to check for errors is the setup and user logs. Here are our docs that will help you locate the logs, depending on your Domino version: https://docs.dominodatalab.com/en/latest/user_guide/164503/view-workspace-logs/
If that doesn't provide you the answer, you'll want to check the support bundle if it's available to you. That can be found here: https://docs.dominodatalab.com/en/latest/user_guide/055b74/support-bundles/
If at any point you see an error similar to this (referring to the .api/token directory):
Readiness probe failed: cat: /var/lib/domino/home/.api/token: No such file or directory
Please try manually logging out of Domino in your browser, then manually logging back in. This should recreate the token in question and allow you to start your runs.
If you try this and still have trouble, please reach out to Domino support and include the support bundle if possible.