the ESN checked in command of U1910 is different as that on frame. load license failed.
1.show license, check ESN is 210235437910C7000001。
2.display elabel slot 4, check ESNis 210235592810D2000005。
3.log in U1910, enter into super mode: delete esn_backup.dat file.
config delete file filename esn_backup.dat
4.restart U1910，when system do the initialization, it finds no esn_backup.dat file in flash, it will re-generate ESN information on frame.
show all files:
esn_backup.dat file date is the latest.
5.compare ESN, now it is same. import license.