When closing an editor it does not reopen

[fredmaggiowski]

Checklist

• your branch will not cause merge conflict with master
• run npm test
• [] tests are included
• [] the documentation is updated or integrated accordingly with your changes
• the code will follow the lint rules and style of the project
• you are not committing extraneous files or sensible data

[fredmaggiowski]

The problem is due to the fact that editor_holder and editjson_card_holder are set only under specific circumstances. While all other accesses where guarded by ifs, there were a few unchecked.

[fredmaggiowski]

This is the error that appeared when clicking to expand the collapsed accordion

[davidebianchi]

LGTM