Fixed a fatal error.
Added edge ngram field types for nouns.
Search API Solr 4.1.x is the unified release that supports Drupal 8 and 9 and a wide range of Solr versions.
The big changes in 4.x compared to 3.x:
Fix the following issues:
#3147938: Automated Drupal 9 compatibility fixes #3020935: Dependencies must be prefixed with the project name
Fix issue 3178930