The 'Writing is not permitted' error may appear when you register or sync a DermapenWorld device you have moved over as an existing user on Apple Smartphones and Tablets.
Please follow the below steps to fix the error:- Close the DermapenWorld App
- Ensure you are running the latest iOS version by checking your smartphone/tablet Settings - General - Software Update
- Clear the Bluetooth list on the smartphone/tablet - Open smartphone/tablet Settings and remove/forget all Dermapen/DP4 Connections from the Bluetooth list (Examples are: 4MD, 4AH,4AH, etc.)
- Reopen the DermapenWorld and Sign In as an Existing User
- Perform a force-sync (hold + Depth and + Speed for 5 secs) till the pen is in Bluetooth Mode with the Bluetooth Symbol displayed.
- Select the Serial Number you want to do the Firmware Upgrade on OR follow the prompts to 'Continue Setup'
- Press Connect & Sync. The pen will complete the Firmware Upgrade and Sync. The device will then power on in Treatment mode.