Suggestions & Solutions:
Some may have a similar error when paired with MSV80.0 DME. Make sure you have a good network connection.
One of our customers failed at 53% in the ISN reading process because his Hotspot speed is too unstable.
Make sure you have updated the app to the latest version.
Backup FLASH separately
If failed, do the Upgrade program, then read again.
If all the above failed, try the solutions below.
Get it done on bench.
For example you can read on bench with autel im608 and gbox.
You can use gbox plus apb15 to read isn from dme, then program the key thru obd since you have the ISN from dme.
It is part of gbox2. It is db15 cable the name. no solder nothing apb15 is like the K line.
The diagram was similar to acdp only can H and can L moved took less than 10 minutes.
i.g Go to immo > bmw> 5 series > e60 cas3 > engine > next it showed read isn and it showed what you needed and how to set up