When configuring Solr Display Fields (admin/islandora/search/islandora_solr/settings), the option exists to link the field's content to a Solr search result. If the content of that field includes a slash ("/"), the search result goes to a 400 "Bad request" error.
The slash is not escaped when the search URL is generated, resulting in this bad request.
Example: the Genre field with content "Dissertation/thesis" goes to the following search result: /islandora/search/mods_genre_mt%3A%22Dissertation%5C/thesis%22
Note the slash in %22Dissertation%5C/thesis%22.
The search works if the / is replaced by slsh manually.
This bug was tested and confirmed in Vagrant.