We are having a NullPointerException in /libs/cq/tagging/gui/components/tagedit/languagepicker/render.jsp because the property "languages" is missing in /etc/tags.
We are not able to add the property (tried crxde and curl) because of the node type, getting: javax.jcr.nodetype.ConstraintViolationException: No matching property definition: languages = [en]
How to fix it?
What version are you using? I tried in AEM 6.3, I am able to add property.
The /etc/tags/ is type of sling:Folder node and languages property is allowed there.
sling-Folder - Apache Sling - Apache Software Foundation
For testing I added languages property in a test node.
Sorry forgot the version. It's an AEM 6.3, that was upgraded from an earlier version.
I tried on a fresh AEM on local and don't have any problem, but the property was already there to start with.
Can you try to delete and and add again if possible or you can create a node of type sling:Folder and try to add there languages property.