TypeError / Canister not found

After upgrading to 0.5.5 from 0.5.4 I got this error when trying to access the canister frontend from a project I created with the former version and wanted to update. I already deleted .dfx/state in the project direcotry and reinstalled dfx.

An error happened:
TypeError: e.Service is not a function    at t.default (data:text/javascript;base64,LyohIEZvciBsaWNlbnNlIGluZm9ybWF0aW9uIHBsZWFzZSBzZWUgaW5kZXguanMuTElDRU5TRSAqLwohZnVuY3Rpb24oZSl7dmFyIHQ9e307ZnVuY3Rpb24gbihyKXtpZih0W3JdKXJldHVybiB0W3JdLmV4cG9ydHM7dmFyIGw9dFtyXT17aTpyLGw6ITEsZXhwb3J0czp ...

Additionally the local replica threw the following error:

Apr 05 23:02:29.381 WARN Could not perform query on canister: IC0301: Canister ic:B5008CEB5C40C41D42 not found, Application: Http Handler

Thanks to our beautiful support the following solution emerged:

What happens is that the bootstrap server JavaScript (which is cached) was changed between 0.5.4 and 0.5.5. They need to refresh the cache of their browser, and the error should go away.