Hi I have K2 2.7.1 on Joomla 3.6.2 and running Hikashop 2.6.3. found a conflict with the Captcha for K2 comments and hikashop register so it would give an error saying it could not verify I was not a robot. The only way I found around it was to disable the K2 user plug in. Please see Hikashop forum post https://hikashop.com/forum/checkout/885947-captcha-cannot-verify-not-a-robot.html for full explaination and some suggestions that Nicolas, moderator made regards improvements to K2 that would avoid the conflict.
Any other suggestions or comments?
K2 is a great platform but this seems to an issue when used with Hikashop.
Regards