Dynamax Crystals not working

[FreakinNerd]

The Dynamax crystals (And15, etc) don't appear to work for me when adding them in via PKHex
When using them it just gives the general cannot use item message from the professor
Anyone seeing this issue? 

[Kaphotics]

There's extra data that is set to the save file in order to specify which pokemon (and their encounter details) are supposed to spawn. Just hacking in the items won't do anything, since that data is missing.

You'll have to wait for future updates to have this documented, as they'll kinda behave like mystery gifts.

[theSLAYER]

To be precise, you gotta at least be able to receive a mystery gift (or tried) to be able to use the Crystals.
Try to receive Meowth, and then after that dyna-crystals will work.

The Dynamax Crystals actually don't have a fixed encounter; their encounters is updated as the software receives soft updates.
I hacked in the items, after my console received a Mystery Gift, and I confirm the 2 specifically named ones works

(The rest doesn't, cause no encounter data tagged to em yet)