Non Standard widgets (sidebar) not supported

I am using YITH Proteo as Theme 1.9.3 together with a child theme. We have a shop on woocommerce. Until now we used in the sidebar a product filter widget from Husky (widget from Husky) but since the last update, it does not work anymore. Actually all non standard widget cannot be installed anymore. Under design-> widget – standard sidebar I choose:

Husky product filter or YITH Proteo Konto Widget, or any other legacy widget (jepack widgets …) and I get ERROR messages: Der Block „yith_proteo_account_widget“ ist von Fehlern  (the block “…” has ERRORS …

What is the issue ? What can I do ?

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