I want to import a flow from somebody else from clipboard but the Import button remains greyed. What are potential causes and what am I supposed to do?
A flow must be valid json in order to import. You can paste it into https://jsonlint.com to see what errors are detected.
Some common faults, usually caused by the application you've copied the flow from, include unexpected newlines and proper quotes " getting replaced by smart quotes.
We have a task on the Node-RED backlog to provide more feedback in the import dialog to help users spot these issues.