Can't render following image

[Yavari]

This code works on the server but is not rendered using the plugin.

@startuml
rectangle rect1 [
== rect1
..
{{
  rectangle nested1
  rectangle nested2
}}
]
@enduml

[qjebbs]

That's because the output of your specific diagram lacks <?xml version="1.0" encoding="UTF-8" standalone="no"?>, while others not. I don't know why PlantUML behaves different between different diagrams.

I've change the detecting method to bypass it.

[Yavari]

Thank you. That was fast. I am looking forward to test this in the next release.