Change record status: 
Project: 
Introduced in branch: 
8.x-5.x
Introduced in version: 
8.x-5.0-rc11
Description: 

Webforms can no longer be translated via the 'User interface translation' (/admin/config/regional/translate). A warning message will be displayed. This prevents the validation error and provides a little more direction on how to properly translate a webform.

Webforms can only be translated via the Webform's (Configuration) Translate tab. To display the Webform: Translate tab enable the Configuration Translation module.

Screenshot

'User interface translation warning

Impacts: 
Site builders, administrators, editors