The most common cause of 400 errors from Solr is the length of the text field that Aspire tries to feed, the default "text" field type has changed and in Solr 5.4.x it uses "strings" which don't allow big strings to get indexed.
To fix it modify the type of it to be "text_general" (in the managed-schema.xml file on Solr) and that should resolve your problems.
This error happpens when you did not configure the Kerberos Authentication.
To fix it, please create a login config property file and set it in the Kerberos Authentication section.
The most common cause of this error if that the keyStore and/or truststore are not set it correctly.
Review and verify the correct settings for the keyStore and truststore.
The most common cause of this error if that the keyStore and/or truststore are not set it.
Review and verify the correct settings for the keyStore and truststore.