The Atlus developed Dragons Crown was released in European markets thanks to NIS America publishing the title in those regions. Atlus sadly had a falling out with them after SEGA purchased the company, leading to NIS America not publishing future Atlus titles. This also has the chance of Atlus titles being removed from the PSN Store front in EU regions, with licenses impacting other titles; one example coming to mind was Capcom’s UMvC3.

 

https://twitter.com/NISAinEurope/status/748417654726266880
Dragon’s Crown is now removed from the EU PSN Store front, with Atlus giving this comment on Twitter.

That doesn’t explain the full story. So what’s going on? Well, it probably has to do with the publishing license Atlus granted to NIS America. Atlus, now owned by Sega, recently announced its plan to cut all ties with NIS America. Dragon’s Crown looks like the first casualty of the publisher split.
Of course, you can still download Dragon’s Crown from the PlayStation Store if you already own it, but if you’re a newcomer, you’re currently out of luck. As some disgruntled potential customers have noted, a heads up would have been nice!
Whether Dragon’s Crown returns to the PlayStation Store is now up to Atlus. We’re chasing it up now.

An Atlus rep has told Eurogamer the company is looking into getting Dragon’s Crown back on PSN, but doesn’t have any kind of timeline yet.
Eurogamer looked into this and gave the above comment. It is a shame to hear that the game is removed, as it was originally a PlayStation Plus title a year or so ago. The game appears to be in many download lists, so at the very least, you could re-download the game if you got it already. PS3 and Vita are also not region locked-so if you want the game, you could also import a PS3/Vita copy or download a digital PS3 copy from the NA Storefront.
Source: Eurogamer

UPDATE: NIS Europe released the following statement on Twitter discussing this news.

Atlus will be publishing the game for EU markets and it will release at a later date.