invisible fonts in admin panel, visual editor missing

[dadapotok]

description:
invisible fonts in admin panel, visual editor missing
more search words:
error - white fonts in text editor, visual editor disappeared

known fix:
This widely known bug and how to fix it is already described here and here:
7 months ago:
​https://wordpress.org/support/topic/visual-editor-missing-15/
in 2013:
​http://www.wpbeginner.com/wp-tutorials/how-to-fix-white-text-and-missing-buttons-in-wordpress-visual-editor/
I had same bug at 2017-03 in WP 4.7.3 and used fix

define('CONCATENATE_SCRIPTS', false);

without any idea of what happened and what am I doing. It worked, but it wasn't a pleasant experience.

Reinstalling WordPress does not fix it, and it always needs a manual fix I thing it is a good thing to report it as a bug

[dadapotok]

text and buttons cannot be seen neither in Visual nor Text mode

[azaozz]

This happens when there are JS errors on the page. Best is to search the ​support forum for the exact error. If none found, paste the errors in a new thread.

See: ​https://codex.wordpress.org/Using_Your_Browser_to_Diagnose_JavaScript_Errors.

[dadapotok]

I'm sorry I can't comprehend this + I already used the fix and replaced my site with test site copy that works fine. All I can say is that 2013 post and 2016 post I mentioned earlier shows that there are a lot of people experience same issue for a long time.

[azaozz]

As far as I've seen on the support forums there is a chance that some cache somewhere is not updated fast enough which sometimes results in js errors on the (old) Edit Post screen. These errors "break" the classic editor, even when they are not directly in it. They usually "magically" fix themselves after some time when the cache is updated.

Best place to get help for these cases is the support forum. There are several steps to try to fix or determine what's the problem.