We have a bunch of logs on previewers instances like the one below:
WARN [image-servlet-pool-88] [com.arondor.viewer.server.servlet.PerSessionDocumentMap] No session created from with request ! request=null
At the time of writing, this log is identified as a false positive, it doesn't prevent the stack to work correctly. Furthermore, there's not enough information to address it.
Request
It should be removed.