Error while using "Get Server response" in Dataset and Query dialog

Hi,

Using Jasperstudio 6.17 on Mac OS Big sur (11.2), I obtain an error when using "Get Server response" button in Dataset and Query dialog. This is quite embarasing.

I used the plug-in for a long time and this error occured with my new computer.

The error dialog is shown attached

Thanks by advance for an answer

Best regards

Syl