[Error after updating to 5.0.5]

I've now managed to fix this - I copied AdvertiserHistory.php from my old folder (Still have this as advised by upgrade doc). 

I have noticed something else which is very strange. Delete is inactive/greyed out for advertiser, campaign, banner. Doesn't matter what I try and select, "delete" I am not able to select delete at the top, it is greyed out. 

Any ideas what the issue is here?

[Error after updating to 5.0.5]

Hi there,

I've just updated to 5.0.5 - had no errors during the upgrade and everything appears to work fine except, when i click on the stats tab and look at an existing campaign I get this:

OA_Admin_Statistics_Factory::_instantiateController() Unable to locate AdvertiserHistory.php

Does anyone know how to fix this?

Any help would be really appreciated, thanks!