Editor not loading anymore

I have several Elementor installations on my server and all running without any problems.
But my latest configuraton installed now does not load the editor at all.
What I have tested so far with no luck:

– Installed complete new WP
– Tried different browsers
– Installed Elementor again
– Deactivated all other plugins.
– Reverted to older Elementor version
– Created new database in WP
– Changed PHP version on server from 7.2 to 7.0 and back
– Recreated wp-config-File

Anyone with a helping hand?

Also this is system info for:

== Server Environment ==
Operating System: Linux
Software: Apache
MySQL version: 5.5.5
PHP Version: 7.2.4
PHP Max Input Vars: 20000
PHP Max Post Size: 256M
GD Installed: Yes
Write Permissions: All right
Elementor Library: Connected

== WordPress Environment ==
Version: 4.9.5
Site URL: https://www.ladenittenthal.ch
Home URL: https://www.ladenittenthal.ch
WP Multisite: No
Max Upload Size: 256 MB
Memory limit: 256M
Permalink Structure: /%postname%/
Language: de-DE
Timezone: Europe/Berlin
Debug Mode: Inactive

== Theme ==
Name: Astra Child
Version: 1.0.0
Author: Brainstorm Force
Child Theme: Yes
Parent Theme Name: Astra
Parent Theme Version: 1.3.0
Parent Theme Author: Brainstorm Force

== User ==
Role: administrator
WP Profile lang: de_DE
User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36

== Active Plugins ==
Elementor
Version: 1.9.8
Author: Elementor.com

== Debug ==
Errors:
ReferenceError: tinymce is not defined
at https://www.ladenittenthal.ch/wp-content/plugins/elementor/assets/js/editor.min.js?ver=1.9.8 – 2:72687
2018-04-16 09:00 +00:00

ReferenceError: tinymce is not defined
at https://www.ladenittenthal.ch/wp-content/plugins/elementor/assets/js/editor.min.js?ver=2.0.6 – 2:88131
2018-04-16 08:36 +00:00

• This topic was modified 6 years, 11 months ago by michelleist-1.
• This topic was modified 6 years, 11 months ago by michelleist-1.
• This topic was modified 6 years, 11 months ago by michelleist-1.

The page I need help with: [log in to see the link]