Huge problems with LG L90, help wanted!

[Android Central Question]

Hi,

Today I've tried to revitalize my old LG L90 with the intention to use it as a flight device for paragliding. About 2 years ago, when it was powered down for the last time, everything worked well.

That was not the case today... It starts OK, but after that I get several error messages, all the time (about once every 2 seconds another message pops-up, even when I closed that same message a few seconds earlier):
Google + has stopped
Google Play Kiosk has stopped
Process com.google.process.location has stopped
Google Play Services has stopped
Process com.google.process.gapps has stopped
I'm also not able to do an Android update. The screen says that the download is in progress and I should check the message screen, but it never shows any download (my internet connection through WiFi is active and working).

When I try to do a factory reset (I don't mind that my old data gets erased), it will reboot first, then displaying a Secure booting error and then the dreaded purple screen of death from DemiGod crash handler.

When I restart my phone, nothing has been done and the phone boots up normally, but with the errors above.

Booting the phone in download mode, results in the same secure booting error, so I can't flash it...

Any suggestions how to (at least) reset the phone to factory settings? Or, even better, how to flash it to a more updated Android version, preferably without bloatware? I'm really out of ideas (and not a hardcore Android user by the way, rarely use it).

Any help would be greatly appreciated!

 

[Rukbat]

Remove your Google account (which, of course, requires the password). That's a new security feature. Then factory reset or reflash.