The game takes a screenshot when pressing the "<|>" key

is your screenshot key set to the | key?
i've just loaded up 1.8.2 and tried pressing the | key, with many variations of alt, shift and ctrl alongside it. no screenshot was taken. check your keybindings in the controls section of the settings

Thank you for your report.
However, your ticket has been resolved as a duplicate.

This issue has been linked to the original bugreport: MC-68399. You can find or add further information on that report.
Please search before reporting any bugs, as it's likely that one exists already.