[Galaxy S II Q&A, Help & Troubleshooting] Python Guy:
I have painted myself into a corner with a Samsung Galaxy S 2. It is my

girlfriend's phone and she wanted to play Pokemon Go. The Android

version there was 4.2 (CyanogenMod) with appropriate Google Apps. It has been

working reasonably well.

Pokemon Go needs to have at least Android 4.4, so an update was due. There was

a CyanogenMod snapshot of 12.1 (Android 5.1) which was installable from within

the old CyanogenMod. I hoped that this would go through well and we did the

upgrade. After the upgrade it indeed had Android 5.1. However, the Google Apps

directly crash, especially the Trebuchet launcher. This means that one cannot

start any apps or use any Google services. Especially the Google Play Store

does not work, it shows the error message [RH-01].

I first thought that we had upgraded to Android 4.4, therefore I installed the

Open GApps nano for 4.4:

(Due to forums policy I am not allowed to hotlink or link to the images.

So this is the best I can do now.)

http ://i.imgur.com/DRHqxNx.jpg

This then (unsurprisingly) failed:

http ://i.imgur.com/qjzrDKw.jpg

At least the error message was really helpful! So then I downloaded Open

GApps nano for 5.1. This then also failed because the GApps that I

have installed together with CyanogenMod years ago were not Open GApps but some

other package:

http ://i.imgur.com/0tI6eEn.jpg

At this point I got uneasy. Her phone turned into a paperweight with a

lockscreen. Since I could not seem to move the GApps forward without flashing

the ROM again, I tried to to so without wiping the data. For this I selected

the update mechanism in Cyanogen Recovery and flashed the Android 5.1

ROM onto the device. After this I tried to install the GApps again. However,

those still fail to install. Here I would guess that the CyanogenMod 12.1

“installer” does not wipe the system partition and leaving remnants of the old

GApps package there.

Since it got late I tried to at least get back to the old state and downloaded

the CyanogenMod with Android 4.2. Trying to flash this failed as the device

type was not picked up correctly:

http ://i.imgur.com/yZ9ilM1.jpg

I do not understand this error. This (or a very similar) version of CyanogenMod

has been present on the device up til yesterday. Why doesn't that work any

more.

A friend of mine suggested to replace the Cyanogen Recovery with the

TWRP. For this I have downloaded the appropriate IMG file from Team Win.

Then using heimdall-frontend on Linux I pulled out the PIT file and put the PIT

file back with the twrp.img file onto the recovery partition. Although the

heimdall-frontend told me that I had a success, there was still the Cyanogen

Recovery.

My current guess is that this phone has hardware which does not allow for a

separate recovery partition unless there is an IsoRec kernel installed. The

CyanogenMod 12.1 should have that, but the recovery is probably the one from

the CyanogenMod 10.1 as the option to update the recovery partition was not

checked when performing the OTA upgrade.

I'm stuck and I have no idea how to get the phone into a working condition. Do

you perhaps have an idea what I could do now?