Javascript file editing stopped working with Eclipse 2020-06

I have been working on the exact same file directory with eclipse for many years. It just worked. I am using PHP, CSS, JS, HTML files.

Occasionally, I ran an automatic upgrade as described here. This also just worked.

Now after the latest upgrade, several things just stopped working:

In PHP files, the core commands are not auto-completed anymore. I searched for a solution, to no avail.
Javascript files don't get any special editor anymore.

Now my most pressing question is:

Where do I re-enable the good old Javascript editor?

Here's my Installation details: enter image description here

The Eclipse IDE for PHP Developers is made up of components from various Eclipse projects. In the Eclipse IDE 2020-06 release the JavaScript support for .js file is no longer provided by the JavaScript editor from JSDT, but by Eclipse Wild Web Developer.

Wild Web Developer does not provide a separate Editor for JavaScript, but extends the Generic Text Editor by code completion, syntax highlighting, validation, navigation, etc. for JavaScript.

To get back the JSDT JavaScript editor you have to uninstall Eclipse Wild Web Developer and install JavaScript Development Tools from the Eclipse IDE 2020-03 release (I guess the problems if you had both were solved by simply removing or disabling the JavaScript editor in the 2020-06 release):

Uninstall Eclipse Wild Web Developer: In Help > About Eclipse IDE: Installation Details, in the Installed Software tab select Eclipse Wild Web Developer and click Uninstall...
Install JavaScript Development Tools from the 2020-03 release: In Help > Install New Software... work with https://download.eclipse.org/releases/2020-03 and choose JavaScript Development Tools to install

See also Eclipse IDE 2020-06 > New & Noteworthy > Eclipse PHP Development Tools

Had the same issue, using 2020-09. I found that Wild Web Developer (in Help > Eclipse Marketplace..) was indeed installed, but then I checked more info and it said