It could be a known issue already but I did not find a task filed for it.
There is a warning in the Console:1. With Minerva skin enabled, go to any page and click on the pencil button - the editing mode will be the source mode. It's not possible to switch to VE.
2. When clicking on Visual editor option, the popup informs that switching to VE is possible after saving which is not true.
```{F12924353}
Your skin is incompatible with VisualEditor. See <https://www.mediawiki.org/wiki/VisualEditor/Skin_requirements> for the requirements.
```
However,3. [[ https://www.mediawiki.org/wiki/VisualEditor/Skin_requirements | VisualEditor/Skin requirements ]] states that VE should work with Minerva skinEnabling the "New wikitext mode" beta feature brings odd looking but working VE.
But sure enough, according to the above warning, it is not possible to switch to VE in Minerva skin. {F12924355}