After Upgrade from 3.3 to 3.5 I got a page with empty dashboard. Also settings will not show anything.
The web developer console in Firefox 59.0.2 let me know:
ReferenceError: angular is not defined[Weitere Informationen] index.php:3:13 ReferenceError: $ is not defined[Weitere Informationen] index.php:75:9
index.php:3 Uncaught ReferenceError: angular is not defined at index.php:3 at index.php:5 index.php:75 Uncaught ReferenceError: $ is not defined at index.php:75
Sorry, was a php timeout by ProxyHttp::compressFile().
I had the exact same issue.
While no specific information was given here on how to resolve the issue, it lead me to its solution.
I share it if someone stumble on this thread looking for a way to make Matomo/Piwik work again.
It's simple: you only need to empty the cache.
See this FAQ for more information : https://matomo.org/faq/how-to/faq_25548/
./console cache:clear or delete everything inside