FinLedger did not start

The page loaded, but the application code did not run. The ledger itself is untouched — this is a problem with delivering the app, not with your data.

Reload the page first. The commonest cause is a sign-in that has quietly expired: the document was served from this device's cache while the rest of the app was refused, and a reload sends you back through sign-in properly.

If reloading does not fix it, open your browser's developer console (F12). A script refused by the Content-Security-Policy means something between you and this site is injecting or rewriting scripts; a script that arrived with a content type of text/html means the request was answered by a sign-in page instead.