Internal Server Error when access payment methods

-- HikaShop version -- : 2.4.0
-- Joomla version -- : 3.4
-- PHP version -- : 5.5
-- Browser(s) name and version -- : all
-- Error-message(debug-mod must be tuned on) -- : Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator at This email address is being protected from spambots. You need JavaScript enabled to view it. to inform them of the time this error occurred, and the actions you performed just before this error.

More information about this error may be available in the server error log.

Trying to get the bottom of a huge memory usage issue on my site, the host has said i need to move to a VPS due to the memory demand for the payments area when accessing it, i've installed a test version and it works fine so i'd really like to get to the bottom of this.

I've uninstalled hikashop and the two addons i installed ePDQ and postcode based shipping module, which i thought might be the problem however when i click on payment methods ( www.vegpods.co.uk/administrator/index.ph...&plugin_type=payment ) i get an internal server error.

i've tried using start and essential mode and still nothing.

I've increased the php memory limit to 128mb and gone through switching most things on and off to see if that helps. But nothing.

Has anyone got any ideas please? Thanks. Ben.

I've set the site up on a test space using a backup or the live site.

i've uninstalled all the payment plugins and i'm still getting the same error, are there any other options please?

Thanks.