Issue in requiring notifications of the Nordic Thingy:52

[WimVerbeek]

I'm trying to connect to a few sensors on the Nordic Thingy:52, and it fails with the following message: characteristic is not defined. The connection to the Thingy is established, but I can't get the notifications. I'm using the NRF52832 to connect to. In the Nordic documentation I found the 'EF68xxxx-9B35-4933-9B10-52FFA9740042' UUID, so I used it, replacing the xxxx by (f.i.) 0201. Any idea about the cause?

[WimVerbeek]

After receiving the nRF52, I activated the firmware update using the Nordic Thingy app, to v2.2.0). Message was 'completed'. So, except for updating the firmware, I didn't change anything of the device.

I use some Javascript (appstore content, so not created by me) in a dev-tool Mendix for connecting to the device, and the connection with the device is successfull. But in retrieving the notifications the message 'characteristic is not defined' is generated. I presume that's a message from the device itself?

The javascript uses the

window.gattServer

getPrimaryService(optionalServiceUUID)
'ef680200-9b35-4933-9b10-52ffa9740042'

getCharacteristic(characteristicUUID)
'ef680201-9b35-4933-9b10-52ffa9740042'

In the Nordic documentation I see:
"To turn on sensor reading, enable notifications from the desired characteristic by writing 0x0001 to the Client Characteristic Configuration Descriptor (CCCD) for that characteristic."
Is this what causes this behaviour?

I used a demo on the Mendix website, where they used the Thingy without problems.
(https://www.youtube.com/watch?v=_83HFXKeRSw , start about 7 minutes in the video)