Failed to execute logstash.javapipeline ] Pipeline aborted due to error {:pipeline_id=>"main", :exception=>#<ArgumentError: The "sincedb_path" argument must point to a file, received a directory: "C:/dev/null">

Elastic Stack Logstash
2

On Windows, if you do not want logstash to persists the in-memory sincedb to disk then set

 sincedb_path => "NUL"

Also, do not use backslash in path option of a file input, use forward slash.