500 Internal server error, during batch enable of translation from the content language settings page

Updated: Comment #0

Problem/Motivation

If create content first, then turn on translation using the content language settings page admin/config/regional/content-language
during batch, get:

Updating translatability for the selected fields

An error has occurred.
Please continue to the error page

An AJAX HTTP error occurred.
HTTP Result Code: 500
Debugging information follows.
Path: /drupal2/af/batch?render=overlay&id=3&op=do_nojs&op=do
StatusText: Internal Server Error
ResponseText: 

But only the first time, going back to the settings page and doing it again is fine.

Note:
@plach #1810386-52: Create workflow to setup multilingual for entity types, bundles and fields

Once all entities are migrated to the new Entity Field API, we are dropping the migration batch completely because then fields will always be stored

Maybe this is a postponed on the issue (a meta?) to migrate all entities to the new Entity Field API... #1818580: [Meta] Convert all entity types to the new Entity Field API

Proposed resolution

(description of the proposed solution, the rationale behind it, and workarounds for people who cannot use the patch)

Remaining tasks

Decide if we need to fix this now, or if it can wait.

User interface changes

No.

API changes

No.

Related Issues

• #1818580: [Meta] Convert all entity types to the new Entity Field API
• #1810386: Create workflow to setup multilingual for entity types, bundles and fields
• (found while testing) #1833022: Only display interface language detection options to customize more granularity