I restarted my HTC One M8 and it has come up with a weird screen

[AC Question]

Top line *** Software status: Official ***
Next line - highlighted in pink: ***LOCKED***
Then 7 lines in green of code etc

At the bottom of the screen three green aliens on skateboards.

 

[B. Diddy]

Welcome to Android Central! That sounds like the bootloader. Select Recovery, and then Wipe Cache Partition, then Reboot System Now. See the detailed steps here: https://support.t-mobile.com/docs/DOC-10672