Try to do 2 things:

1)Go to Recovery menu by pressing Power+Volume Up (When MEIZU logo appears, release the buttons).
Select the System Update option and un-select the clear data option. Then connect your phone to the computer via the USB cable. When the "Recovery" disk appears, go to the Flyme 6 Public Beta forum thread(http://forum.flymeos.com/thread-22658-1-1.html), download the firmware file for your device, then copy the file to the Recovery disk. (WARNING: Do not rename the file. Leave it as "update.zip".)
Then disconnect your phone from the computer, press the Start button, and let it finish. After the firmware flash is complete, test your phone if it works. If it didn't work, go to Step 2.

2)Bad news, you have to downgrade to Flyme 5. (WARNING: To downgrade, you must clear user data to avoid corrupting your data. Please select the clear data option in the Recovery menu before downgrading as described below.)
Go to Recovery menu by pressing Power+Volume Up (When MEIZU logo appears, release the buttons).
Select the System Update option and the clear data option. Do the same with Step 1, but this time go to the Flyme OS Official Page (flymeos.com) and download the latest Flyme 5 firmware that worked (Flyme 5.1.12.0G I guess). After download, copy the firmware file to the Recovery disk. (WARNING: Do not rename the file. Leave it as "update.zip".) Then disconnect your phone from the computer, press the Start button. Wait for it to complete. After downgrading, test your phone to see if it works. Complete the setup and configure your settings. (Note: Google Services & Play Store is pre-installed again, so you do not need to download them from Hot Apps/App Store)

I hope my advice was heplful. Reply to contact me.

Bajiru

Really? What was it?

So, lesson learned. Do not install unofficial launchers (system or third-party)!