@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/vpbtiw915cvlzoa6xtq12m-ywwyjv8... to http://www.plantuml.com/plantuml/png/~1vpbtiw915cvlzoa6xtq12m-ywwyjv8... 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: vpbtiw915cvlzoa6xtq12m-ywwyjv89ntxa1rktczolu5lwousu5l2p8t95tq4bg6mazzflxmpjxwqw5 ltcu_7zd_lyp0nhkwgpkr_bimrngfjcara-a37dbcmjfm6qwq_eqspvbnitwftu6trfh4unzv2r9m0r6 kked6b2dg5phq3o-pfoaxr2eezbi6newcyrz3l1g3mefujgkogf75plicmqukrn2foyxbl0t8dhetpnd pa1a3cjp8uc9qsuql23se3bnp7boiggzurvwchsbmy0swico0i9d1pxmeiqak4icxl0jyntlwmpefufy fndx4pfj-xg_khkv9wtew1kxcyk2nioareqnd48r9n7lllmlv1kpgx88sbvderdbhteuloi4egykklsr 8ifqg_yhh7-_s9wpnxvsw6anvpckye-jc7k3ciysn2owppwocezmetd0ttxqkst7v2-epil1nkqvfrsp fzw4h2xzk-teroip_i2w-uv-rpn0kfboam9_0g00 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