I installed elementary os recently, I am new to Linux .I don't know what exactly it works, but by the help of YouTube videos I installed and dual booted Linux(elementary os) on my dell laptop.I loved it , good one ,high speed.But recently it shown an operating system update via app store I downloaded, but it was not completed , battery drained completely before completing download.After that when I tried to login it shows error that unable to login: starting session has failed.(session returned error code 1).I found and tries a method available which was editi g some file inside os,but it was not working perfectly as editing file was not worked perfect.I am a beginner , I don't have much technical knowledge.Can anyone please help to finding out what is the actual problem!?help me to fix it!? I am attaching my problem screenshot.
Depending on how you've originally installed eOS there's a good chance you can boot into a 'recovery mode' (via the Grub menu) which is normally accessed by holding down the
esc key immediately after turning your system on, or a restart process begins, and then only after any BIOS entry shortcut has timed out. If your system boots into the Grub menu you'll know it - minimal text based menu navigated by arrow keys with menu items labeled with the operating system the selection will boot into.
Recovery mode (if it was installed) would then be under the main menu item labeled 'Advanced elementary os options'. Select that and it should give you a list of secondary boot options - one of which should have 'recovery' in its label.
After selecting a recovery boot option - another minimal looking menu eventually comes up. That one will have options centered around recovery specifics all of which are relatively safe to pick from. Can't say those would fix your login issue - but they're worth a try.