The Nexus Devices, which are manufactured in collaboration with several smartphone producing companies by Google, are usually the first ones to get the major updates. This was the same case with the latest Android version 5.0 Lollipop update too (though this time Moto G 2014 broke the record), but it may hurt the users to know that there are some major issues with the update in their Nexus Devices, especially the 2012 Nexus 7 tablet.
Though the new version of Android was said to have bug fixes for various problems in the older devices and versions, it is clear that the version itself has some bugs. The users have reported to have problems in running some of the most-useful apps, for example- Chrome. Firefox also has some issues in running properly, the keyboard is taking like forever to load, and according to some of the users, their device is not ‘usable’ at all. The Android 5.0 Lollipop reported to cause problems also in the installation of Apps built with Adobe Air (error 505), which are removed automatically from the device.
The advice from the experts suggest that the installation of wrong factory images is the major cause of the problem. To elaborate, if you have a WiFi version 2012 Nexus 7 grouper model, and you use a ‘Nakasi’ version factory image to update your device, this would cause problems in it. Hence, the suggested solution is not to use the factory image for update, and use the OTA update instead.
If you have the update installed via factory image already, you can downgrade your OS to 4.4.4 KitKat again, and use the OTA file to update your device.
You can try going to the recovery mode (press and hold the volume down and power button simultaneously for this, and clear the cache partition before having a reboot.
Make sure that you have sufficient free internal storage available in your device, as this may be another reason to make your device laggy.