Overview

This Knowledge Base article provides an explanation on restoring content of corrupted or lost Salesforce Knowledge Articles, including the limitations.

By default, Knowledge Articles are excluded from backups. To enable backing up and restoring Knowledge Articles, the following conditions must be met:

Lightning Knowledge must be enabled in your org to enable backup of Knowledge Articles.
A user must have the View Articles permission enabled.
Salesforce Knowledge users, unlike customer and partner users, must also be granted the Knowledge User feature license.
Multiple Languages must be enabled, in the Knowledge Settings of Salesforce Setup.

About Knowledge Articles

The Basics

Knowledge Articles in Salesforce are special objects. Restoring Knowledge Articles is different from restoring other objects into Salesforce.

The Salesforce parent object for Knowledge Articles (*__ka) cannot be used for backup, as it is only the metadata of the knowledge article. From this object, other versions can be derived - KnowledgeArticleVersions and their associated *__kav objects - where the data from the Salesforce Knowledge article is replicated, and backed up.

Status and Versions

When a knowledge article is backed up, we create versions of the article, where the data is replicated.

There are three publication status types for any given knowledge article:

Draft - Only one draft version can exist (at a time) for any article, for any given language.
Published - Only one published version can exist (at a time) for any article, for any given language.
Archived - Multiple archived versions can exist simultaneously for any article (for any given language).

NOTE: Archived versions of the knowledge article cannot be restored to Salesforce, only draft and published versions can be restored.

Data Loss or Corruption

There are three possible scenarios for data loss or corruption:

Data loss (entire article) - An entire knowledge article was deleted - the article was lost, along with all of its versions (drafts, published, and archived). When restored, the entire object will be restored, as it was backed up, except for archived versions.
Data loss (draft version/s) - One or more drafts were lost (multiple draft versions can be deleted, one draft per language). The restore procedure will overwrite any existing drafts, if they exist.
Data corruption - Version content was changed, or publication status of Version was changed (e.g. A draft was published, or a published article was archived, or a draft was published and then archived). The restore procedure will overwrite any existing drafts, if they exist.

Restoring Lost Data

In order to restore Knowledge Articles, we need to create new versions of each article. When data corruption occurs in a Salesforce knowledge article, the data can be restored from the replicated object versions in the backup (from the *_kav objects).

Other Considerations

Since only one published version and only one draft version of an article (for any given language) can exist, at any one time, then all other versions of the article are archived. There can be numerous versions of the article in the Archive state. However, the Archive article versions cannot be restored back into Salesforce. Only published versions and draft versions (for any given language) can be restored to Salesforce.

Since only one draft version can exist (for any language), at any one time, when a new draft version is created, it overwrites the previous draft version of that article. Therefore, you need to be aware that when creating a new draft version of an article (for example, when editing an existing draft), then the previous version of that draft will no longer be available.

The same applies to the published version of an article. Since only one published version can exist (for any language), at any one time, when a draft version is published, it overwrites the previously published version of that article (for the given language). Therefore, you need to be aware that when publishing a draft version of an article, then the previous version of that published article will no longer be available. To preserve the previous version of the published article, before publishing a new version, you must first archive it (create an Archive version of that published article).

NOTE: When restoring a draft version, the existing draft version (of the same language) is overwritten.

Beware that if you manually back up a Salesforce org after data corruption has occurred in a knowledge article, then the knowledge article with corrupted data might replace a previously backed up knowledge article object that may have had uncorrupted data.

Remember that when a draft version is published, then the existing published article version is overwritten by the new published version.

In Salesforce, performing a “Restore” on an archived article, converts it to a draft version. The draft version can then be restored. Keep in mind that this action will also overwrite any existing draft version, since only one draft version can exist at a time (for a given language).

NOTE: Archived versions of the knowledge article cannot be restored to Salesforce, only draft and published versions can be restored.

NOTE: The Nodes template supports the seeding of knowledge articles. You are required to add the *_kav object as a root node in the Nodes template.

NOTE: Knowledge Articles in all languages are supported by the Backup and Restore application.

See here for the procedure of restoring a Salesforce knowledge article.