I have a 404 not found error when I click on "customize", "editor", or try and edit any post or page. The problem also occurs when I try to enable the Astra Pro "new header/footer customizer".
It is not a theme or plugin related problem. I have changed themes and eliminated all plugins. Even if I create a brand new WP site thru Cpanel the problem will exist on that site as well. This leads me to believe it's a host/cpanel side issue or some change made in the plugin update.
The problem goes away with Ultimate Addons for Gutenberg v 1.25.6. If I upgrade to any newer version of this plugin all the way up to 2.0.15 which is now Spectra then I get the issue. Brainstorm force who are the makers of the Astra theme and the Gutenberg/Spectra plugin have been trying to figure this out for 2 months and I'm losing patience.
- switched themes - same issue
- Created brand new WP site via Cpanel and installed only Astra and Spectra - same issue on new site
- Roll back to UA for Gutenberg 1.25.6 - problem goes away
- Update UA for Gutenberg to 2.0.0 thru 2.0.15 - problem comes back
- Tried the fixes previously described on this forum - same issue