User login issues after site duplication

Hello,

A friend has asked me to look after their site as the designer they had hired had not done what was asked. We used the duplicator plugin to transfer the site across to my server. This all seemed successful and everything seems to work as required except for the user login section.

When a user registers, the page seems to hang but does actually add the user to the database. When you try to login, it says login successful but does not display the logged in pages, just continues as if the user hadn’t logged in.

I’m not sure if this part worked previously, my friend says it was temperamental. The site address is http://www.farmandplantsales.co.uk. The theme is Spotfinder, with the Business directory plugin.

Other plugins are:
BackupWordpress
Contact Form 7
Redirection
Revolution slider
Store locator
Wordpress importer

I’d really appreciate any help with this. I’m a bit stuck where to start as I have checked the site settings and it all seems to be in order.

Many thanks,

Graeme