Hi,
If you have blank page, it means you have a PHP error.
By activating the joomla debug mode and changing the error reporting level in the global joomla configuration (system & server tabs) you could retrieve more information directly from the website.
Otherwise, you have to check your PHP error log to see more details about the error.
Without this error report, we can't know what happening exactly so we can't know what as to be fixed and where.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.