I am trying to work on a large Javascript file in Jetbrains WebStorm 8 and I am getting a message at the top of the editing window that says:
File size exceeds configured limit (2560000). Code insight features not available.
How can I increase the 'configured limit' to get access to all features?
In IntelliJ 2016 and newer you can change this setting from the Help menu, Edit Custom Properties (as commented by @eggplantbr).
On older versions, there's no GUI to do it. But you can change it if you edit the IntelliJ IDEA Platform Properties file:
#---------------------------------------------------------------------
# Maximum file size (kilobytes) IDE should provide code assistance for.
# The larger file is the slower its editor works and higher overall system memory requirements are
# if code assistance is enabled. Remove this property or set to very large number if you need
# code assistance for any files available regardless their size.
#---------------------------------------------------------------------
idea.max.intellisense.filesize=2500