[KevinH]

Depending on your version of Sigil, you should make sure you return a non-zero value to ensure the error log is shown (things written to stderr).

Also make sure you have not enabled the "autoclose" in the plugin.xml if you are using a build from master. If this is in a validation plugin, then reporting no errors will allow it to autoclose.

You are also seeing the result xml being sent back from the launcher.py code in the plugin framework back to Sigil. I am not sure how you are seeing this? What exact version of Sigil are you using?

KevinH