"Cannot prepare content preview in Page mode. The language has not been added to any siteaccess. Please update your configuration." error occurs when entering eZ Platform folder.

Steps:

1. Prepare installation with clear studio-clean database.
2. Go to Content / Content structure.
3. Enter Home / eZ Platform folder.

Issue: "Cannot prepare content preview in Page mode. The language has not been added to any siteaccess. Please update your configuration." error occurs (attached).

Remarks: Originally introduced here: https://github.com/ezsystems/StudioUIBundle/pull/726.
On 1.13.0 folder is not present.
Does not occur on 2.1.0.