This is a known issue seen in Studio Community (STS) after recent updatesPublishing Test Cases to Orchestrator can fail if Testing/Test Manager is not supported or enabledfor the Community tenant.
Please verify you’re connected to a validCommunity Orchestrator, try signing out/in of Studio, and reconnect Orchestrator. If the issue started right after the update, it’s likely a product regression, and reinstalling a previous stable version or raising a support/community ticket with logs is recommended.