bluetooth wont even turn on after upgrading from lollipop to marshmallow

[HBzz]

i've been using LG Magna with android lollipop for a year now and got a notification last night about an android os upgrade. i downloaded it and got android marshmallow 6.0. everything was working just fine but today when i turned on my bluetooth (to transfer some files), it didnt turn on. instead it showed an error message saying: "unfortunately bluetooth has stopped"
i went to app manager, tapped on "Bluetooth" (having the blue bluetooth icon), cleared cache and cleared data. did the same with another app "Bluetooth" (having the settings icon) and an app "Bluetooth MIDI Service". then i tried to turn on bluetooth but same problem occured. then i restarted my phone. when it booted, the same error message appeared "unfortunately bluetooth has stopped" (even though i hadnt even tried to turn on bluetooth yet). i still tried to turn on bluetooth and of course the same error message appeared. i've never had this problem before the upgrade so im pretty sure that the problem lies with the upgrade.
i also went to app manager - menu - configure apps - ignore optimisations cuz i had a feeling that maybe the battery saving feature of marshmallow must have something to do with the problem so i checked the three apps i mentioned before ("Bluetooth" "Bluetooth" and "Bluetooth MIDI Service"). still didnt solve my problem.
another thing i did was that i went to settings - backup & reset - networks settings reset. still no use cuz the same error message appeared "unfortunately bluetooth has stopped" (again even though i hadnt even tried to turn on bluetooth yet)
the only solution left in my mind is to factory reset my phone but i really dont want to go through all the hassle after doing so especially if theres a possibility that my problem wont even be fixed by resetting. please help.

sorry for the long post. way too lazy to post a potato

 

[B. Diddy]

Welcome to Android Central! Does this happen in Safe Mode as well? How-to: LG Magna: Clear App / Phone Cache; Reboot in Safe Mode

 

[HBzz]

Welcome to Android Central! Does this happen in Safe Mode as well? How-to: LG Magna: Clear App / Phone Cache; Reboot in Safe Mode

Yes it still happens in safe mode.

 

[B. Diddy]

In that case, it's probably a problem with the firmware itself. You could try using something like LG Bridge to reinstall the firmware--but if the firmware itself is actually buggy (i.e., if it's not a problem with a corrupt firmware), then the problem will persist.

 

[HBzz]

In that case, it's probably a problem with the firmware itself. You could try using something like LG Bridge to reinstall the firmware--but if the firmware itself is actually buggy (i.e., if it's not a problem with a corrupt firmware), then the problem will persist.

I'm no expert so I don't know what's LG Bridge or how to use it or what reinstalling firmware would do. Can you please provide instructions on how to use LG Bridge on my phone?
Otherwise, is there any way to downgrade my OS back to Lollipop? If so, then how should I?
Btw I forgot to mention, my phone isn't rooted (I don't like to complicate stuff)

 

[B. Diddy]

See if this helps: How to use LG Bridge with your LG phone | Android Central

 

[HBzz]

Apparently, LG Bridge is not supported with my phone so I had to download LG PC Suite instead. When I did so, I connected my phone to the PC via USB cable, opened LG PC Suite on my PC and clicked on 'Check Phone Upgrade', it told me to disconnect my phone from the PC, then 'Change from USB connection mode to "PC Suite" on your phone and reconnect to the PC'.
If by this, they mean that I have to choose some option "PC Suite" on the 'USB PC Connection' screen that opens on my phone whenever I connect it to PC, then that's not possible cuz the only options I'm shown are:
Charge phone
Media device (MTP)
Send images (PTP)
MIDI device
there's no option for PC Suite

But if they mean that I have to change USB connection mode BEFORE connecting to the PC then I have no idea how to do this on Android Marshmallow. I tried hard to find this in my settings but I just can't. I'm regretting the upgrade so much:'(

 

[HBzz]

Ok so what I had installed was LG PC Suite IV. I uninstalled it and downloaded LG PC Suite instead and connected my mobile to the PC via USB cable. Connected to LG PC Suite. Now what?

 

[HBzz]

I don't think I can do much with LG PC Suite except back up, restore, sync, etc. If i back up, factory reset my phone, then restore would my problem be fixed?

 

[B. Diddy]

Sorry this is such a hassle! These kinds of manufacturer sync/backup programs are often a little dicey, and aren't always compatible with all of their devices either.:-\

You could always do a factory reset, but I know you were hoping to avoid that. Now that you have a means to back everything up, it hopefully will make the restore process painless. Just make sure it backs up everything that's important to you--e.g., if saved text messages are important, and you find out afterwards that the program didn't back up SMS, then you'll be ripping your hair out.

 

[HBzz]

Yeah i was also thinking of factory reset. If it didn't work, then I'll just take my phone to the nearest customer service center.

Anyway, thank you so much for your support during all this time. Even though we couldn't solve the problem, I would have been really frustrated if no one answered to my questions as quick as you did. It was a comfort knowing that someone is there to help.

 

[HBzz]

Factory reset worked. Bluetooth is back to normal. Didn't lose any important data either. If not for this Bluetooth issue, I would have loved Android Marshmallow especially because of the feature to choose different permissions for different apps. Anyhow, problem solved.

 

[B. Diddy]

Great! But keep an eye out for the problem returning ...