Png file generation issue

[OlivierJourdan]

For the record, the discussion about this issue started here --> https://asciidoctor.zulipchat.com/#narrow/stream/279642-users/topic/asciidoctor.20diagram.20using.20kroki.2Eio

When I run the same command twice, the second execution results with empty png files.

Here is a video demo of the issue:

As you can see the second time I'm running the command, png files became empty (1 kB). SVG files are correctly rendered.

Here is the file used for the test --> Diagram generation test.txt

OS: Windows 10
Asciidoctor installed with ruby: asciidoctor, asciidoctor-pdf and asciidoctor-kroki
CLI command: asciidoctor -a kroki-fetch-diagram -r asciidoctor-kroki "C:\Users\team\Desktop\Diagram generation test\Diagram generation test.adoc"