Unable to MapViewOfFile in MapChunk. Error code 8

See this thread.

Hi there!

This Error message is usually in relation to a lack of available physical memory, or corruption within the game files. Please perform a Pack check as detailed here.

In particular it may help to add "-gc 2" to the end of your Path of Exile shortcut target location if you're playing on the standalone client (It should look like this: "C:\Program Files\Grinding Gear Games\Path of Exile\Client.exe" -gc 2), or your Launch Options if you're using the Steam Client. For more information on this, please visit this thread.

-gc 2 is garbage collection, it cleans out some stuff from ram each time you change area.
It does not prevent the error from occurring but it can slow it down enough so you may not see it during normal play.

I hope this helps!