Steps to reproduce:

1. Create some images via Image Content Type.
2. Use Solr as a search engine - run the ibexa:reindex command.
3. Change the Tags field in the Image Content Type to ibexa_taxonomy_entry_assignment - choose Tags as Taxonomy in configuration.
4. Try to add any image using the "Image" button in Rich Text Editor to any Rich Text field.

Result:
One is presented with an exception in the Image Library component:
Could not find Field 'value' in 'ibexa_taxonomy_entry_assignment' Field Type's index definition

Expected result:
The Image Library should properly list contents.