We are trying to integrate search_api_solr & search_api_solr_attachments with Acquia search in Drupal 8. So far I got to the point where the search_api_attachments is returning the following message: "Solr HTTP error: Internal Server Error".
I tried to obtain the Apache Tomcat stacktrace in SearchSubscriber::postExecuteRequest(), but there are no details from the Exception present in the response. I have also installed an Apache Solr 3.5 on my local machine with solr-cell libraries and everything is working fine.
Can you confirm if there is a problem in the extract/tika servlet?
Basically I am using latest -dev modules with some patched issues to make it work.
I am attaching a screenshot of the configuration screens.