I followed the guide to upgrade to Ionic 5 (after solving all deprecated warnings) and also to Angular v9.
On the first build, I got a bunch of errors NG8001 is not a known element (for header, title, buttons, menu-button etc).
I searched the web and there was just one occurence of this error by a guy who placed a question on the same issue today!
Any idea how to solve? Many thanks!
I found the issue, a file called "zone-flags.ts" should have been present (it's there on a new v5 project), but was not in the upgraded one. I copied it over a brand new v5 project, and all is well now... Dont know why it wasnt created by the upgrade.
Thanks!