After upgrade to Magento 2, in IDE PhpStorm, the UI component file show a lot of errors , like Element argument is not allowed here, Element xxx is not allowed here etc.
But, the UI component file is working well in system. And the official UI component file also has the errors. Like cms_block_listing.xml:
How to fix it?
Go to File > Setting > Plugins > search text ('Magento2'); install this plugin after that click regenerated urn map and reindex in Magento2 Plugin config . Good luck!
File > Settings > Magento2 Plugin. After click "regenerated urn map" button, we need restart PhpStorm to see effect.
Other than the solution which install Magento2 Plugin in PhpStorm, we could also use the Magento official CLI command:
bin/magento dev:urn-catalog:generate .idea/misc.xml
It will generate the urn map file which PhpStorm need. Restart PhpStorm, then the a lot of errors will disappear.