When using the InDesign 2020 plugin on macOS Catalina, the following error message displays at startup:
"Unable to open "PictureWrangler ID CC 2020.InDesignPlugin"; Application comes from a developer that cannot be verified."
This error message is caused by the new macOS security features added in Catalina. The issue has been communicated to our Engineering Team, who are working on a fix to notarize the plugins.
Until the fix is released, as a workaround, executing the following command in the Terminal will disable macOS Gatekeeper, the process responsible for blocking the plugin:
sudo spctl --master-disable