@rafal: I have the same issue. Im on a Mac OSX Sierra - and do have graphviz installed via homebrew. dot - graphviz version 2.40.1 (20161225.0304) I tried with both the version of schemaSpy that is publicly released (v5.0.0) and the release candidate (v6.0.0-rc1) jars - both have the same issue. This the line that gets repeated for various tables: .org.schemaspy.util.Dot$DotFailure: 'dot -Tpng:gd ./tmp/diagrams/XXX.1degree.dot -o./tmp/diagrams/XXX.1degree.png -Tcmapx' failed with return code 139