@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/%22//www.plantuml.com/plantuml... to http://www.plantuml.com/plantuml/png/~1%22//www.plantuml.com/plantuml... 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: %22//www.plantuml.com/plantuml/png/jLJDQjj04BxFKmo-v2Jm_Xn32EqZvEW6eKHRIrXQcTqrn OIyUrl7EnrjD4QqrAUnlf-HvXlcCQOcfDCu0CH3xuzDQ4Py0qJ4eVSkdOyEfv2wwVBeTHgFatS-FQNpu 32urzJu_U3W7Q3hMuVtzqDpdaxfuG5ZSi5DlmrA2824kDbki8cu3trRR-ijPp6I-aDICeaxAO6aEKaB9 CD9HY1PJh82wHlWmk_Vdx8tDBNwRytPjFIQGTWv2IZMAlJxBbKK8KFQwOUlA3R8HG5eo4K16CX50LW2g 7l-aDa2FfrZSYD-R4-y_AaLlitt7JSe_BwSOaGbeJFJ-kKNjrQbyrSgrPnEd5iQBMaqN4H5ypmaiSbwl hxmxrBNHtm9hZd4ZmTBrjS8TbtVjiu_LujsxqkvpBvFVyfbnwQ7GltC7UIfSYyjQRIiCPB6o1gBh9Rqb f8ia1mFZLLuOr4ykE_ffjX8OhEYirrErF14ZPXecPoP9RVeRBcpNUri_s8dxAS9yqdP5HdPOlVfyj6vo YE5N12I3p_aejHOeADT80PoWTKLgkXuGou88vq24iu_RkUdqFY3j7ntrzEmT1RqTGCBXo8GuQ2GKkuDZ ywtft7u2G00%22 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