@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/ZP91IyGm48Nl-HN3xkUpUfF7opR4WG... to http://www.plantuml.com/plantuml/png/~1ZP91IyGm48Nl-HN3xkUpUfF7opR4WG... 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: ZP91IyGm48Nl-HN3xkUpUfF7opR4WGqA0aKlasPLYPAslAtsT0kY6KQmB1NlVdwWjbwX5STEsCoI30pC rCdcNdScLq5JukImcVyDizYg8enBm-WuNKflj0jhEuwD4dtNs_nRnzQSjeV7TlBFV3AZIRB0J8HGyYOG RWO0v8G0beKvSogWHU5z2H_kTwjwq5Jh3W6FbWfdAozLE_aEPcTlxykAy_ZHsWG0Id6u0XUhB9ry0F0p OD3dVtSRG0JO3wANMnz8WAI2Ca2psgbzEELRLNMY1nd4j482IP7zfLxt8K5zZdx-mTDxw2niqh1wQbMC _TX5txFwDplNRXI4SSfYN3T6kUab5tvHmtoGdNYnE2Uj25hSBgYKn4W_PbmPy8YlUaGgX2HjLczkYzLx iZ3LNS8wcNmcK7s8Jh594OsaTxKsxGi0 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