@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/vl91ji905dtt51fsn80odapdz44z9n... to http://www.plantuml.com/plantuml/png/~1vl91ji905dtt51fsn80odapdz44z9n... 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: vl91ji905dtt51fsn80odapdz44z9nzqkiopmpatbh23h4rdf91892gkmayui8pel9hmcqvbr-6qfqkb ndny-vfuxtllbs564f06fq5xp6-wnq82znfdwrjx_llfulaxhedkpe7me1wz1ge-zzbpjywvdp8aa3ed weael8plh3nxmgqltfim0dh1eatggcgmz1jgpq1m01bgmjo-qpgd1a6xcigehwyy4oc6bkr-fuylkda9 kidohstueffdhjznwjdybwo8maikhgyoovbw65t5rcgoyy59hnwrcaoq5plh2y_o588o_jagm4ucbc2m l59gud9rpcaa8eyxneesx3jh-nzprwszkwwxudw6qsjph65jl8kgqds-lowluvpbqevmqveieoyr37pr yyaykh8umzhrstzbdlwbmaic1eqmubpxpj1_vnpdx-jxouzhinglq8tpati9berlthkfn0hnnn_nvwzu t5-rzsr_xihy9gnbncqkyuidlxxuffkkxgy0 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