Hi, i’m looking at using PlantUML and have been able to successfully create use case and sequence diagrams (with the caveat being there is no dynamic edit capability without having to save the text separately and amend that)

but i am unable to generate a JSON diagram and getting a message stating 

Unable to render diagram. Please check the code for errors and try again.

i have just cut and pasted an example from the PlantUML documentation

thanks in advance

Andy