We logged this with Qlik support who informed us that this is due to the central node being configured with 'Node Purpose = Production", disabling the button.
Once we reconfigured the node purpose to "Both", the button reappeared.
Guess this depends how the site is configured, but ours is sort of a mixture of development and production apps at the moment and so the central node needs to cater for both.
eightieschild has answered correctly, but from a support angle, here are the primary reasons why the Create App button is unavailable
- Node Type is set to Production (see https://help.qlik.com/en-US/sense/2.2/Subsystems/ManagementConsole/Content/create-node.htm "Production: this server is intended to support users to access apps but not create them. This means that when a user connects to this node, the buttons in the Hub to create apps and the My Work section are not displayed to the user."
- Security Rules: by default the CreateApp security rule should apply here, but may've been fiddled with or disabled
- Users are logging in as Anonymous (CreateApp by default is that all users except anonymous).