Hi, As a newbie, I try to install e-0.8-n-2020041349483-dev-hero2lte.zip on my phone. Heimdall works well, adb reboot recovery from my Ubuntu 18.4 LTS works well and I arrive to Android recovery modus.
When “Apply update form SD Card”, error 21 occures:
E: failed to verify whole-file signature
E: signature verification failed
E: error : 21
I first wiped out all data/factroy reset and cache partition
Could you help me fix this issue?