Hello @Salah_Mohamed ,
It can be a little tricky to determine exactly the root cause of what you are seeing. This could be a simple as PME is not communicating with the device to more complex interactions between PME and windows Registry. When selecting diagram from meter's template. PME takes a number of steps. First is to find the DeviceInfo key in windows registry, then find the device type key, then defaultFirmware then device specific information.
You can see example below.
The information the data field is if the folder and diagram name PME will try to open. There are a lot of moving parts and determining where something has gone wrong can be a challenge. I would start by using a program called procmon from live.sysinternals.com. You can see all of the keys/values PME is trying to access when opening the diagram. Perhaps PME is not opening the devicetype you think it should. Or value in data field does not match what folder and diagram are called. Or folder and diagram names do not match.
There is sadly not a single answer to explain why you are seeing this error.
Regards,
Charles
L4 Prime for Advanced metering and Utilities