@startuml legend The plugin you are using seems to generated a bad URL. This URL does not look like DEFLATE data. It looks like your plugin is using HUFFMAN encoding. This means you have now to add an header ~1 to your data. For example, you have to change: http://www.plantuml.com/plantuml/png/bLHTIyCm57s_l-8ywh9IEgQ8e0moLd... to http://www.plantuml.com/plantuml/png/~1bLHTIyCm57s_l-8ywh9IEgQ8e0moLd... It will work this way You may contact the PlantUML team at plantuml@gmail.com But you should also probably contact the plugin authors you are currently using and send them this image For the record, here is your data: bLHTIyCm57s_l-8ywh9IEgQ8e0moLdoHG1PzsKlcnYoKLhQo-P0VhxrT4mqMzJoCd7Fknyr7DpiqTjzi YiPQmY3qP0qvw2SCSVRr53BEjf1mv8D5bCtQsTTP1eU0l4hpjpRT0UGBk2YVDTTFoC4ntEy-20oH276U Kr-b-WQoqmHhVSptRJle_1dIw-n1THhwcELy4Ow2OqFDM8iumIDCFwXn3v endlegend @enduml Submit amiga aws-orange black-knight bluegray blueprint cerulean-outline cerulean crt-amber crt-green cyborg-outline cyborg hacker lightgray mars materia-outline materia metal mimeograph minty plain reddress-darkblue reddress-darkgreen reddress-darkorange reddress-darkred reddress-lightblue reddress-lightgreen reddress-lightorange reddress-lightred sandstone silver sketchy-outline sketchy spacelab spacelab-white superhero-outline superhero toy united vibrant       🎉 Discover the future PlantUML Web Editor! 🚀  PNG  SVG  ASCII Art