The error message
"Failed to enable camera barcode scanning. Error 23: The Scandit SDK license validation failed. The external id does not match with the license key."
refers to a mismatch of the Epic CID within the Scandit license key.
The Scandit license key has a reference to the CID included to avoid the use of the license key outside of the corresponding hospital/Epic instance.
In order to solve the issue, you need to have a new license key with your correct CID encoded.
For trial subscriptions of the Scandit SDK in Epic Rover, you can create a new key on your own in your dashboard ssl.scandit.com
In case you have a paid subscription, please reach out to us directly via the support request form
https://support.scandit.com/hc/en-us/requests/new
and let us know your Epic CID.