In a multilingual environment, you are getting the following error when trying to add sub taxonomies to particular taxonomies:
Error occured while executing cms_createtaxonomy: The INSERT statement conflicted with the FOREIGN KEY constraint "taxonomy_children_tbl_fk1". The conflict ocurred in database "CMQA87" , table "dbo.taxonomy_tbl" . Warning: Null value is eliminated by an aggregate or other SET operation. Referrer: ...Workarea/taxonomy.aspx?action=add&parentid=25276&LangType=1033
The following steps are the best way to make sure that the languages are applied to all the taxonomies, to resolve this error:
1. Go to the settings tab >
localization > Languages and Regions.
2. Note all of the enabled languages when you click "Enable"
3. Uncheck all of the languages, and then "Update"
4. Click enable again, and re-enable all of those languages again, and then "Update"
5. Try to add a taxonomy where you weren't able to.