Most "map won't load" issues are one of three things: a stale bundle, a permission mismatch, or a very large map hitting a timeout.
First: hard refresh
Cmd+Shift+R (Mac) or Ctrl+Shift+R (Windows). Cached JavaScript from an old deploy causes about 60% of the reports.
Check the permissions
If you're viewing a map shared by someone else, they may have unshared it or downgraded your role. Ask them to re-share or check /account/settings for what you actually have access to.
Very large maps
Maps over ~150 stages or ~50 runs can hit browser memory issues on older machines. Try reducing runs shown (via the filter) or opening the map in a Chromium-based browser (Chrome / Edge / Brave) which handles the workload better.
Report a stuck map
Open browser DevTools > Console, screenshot any red errors, and email them to support@mapvs.com with the map URL. We can usually reproduce and fix within a day.