Update to J3.4.7 - cant add item to shopping cart

[GJC Web Design]

yes.. what other explanation can there be if you are able to add etc?
is he a return client?

[sabikeuk]

Customer confirmed it was the first time he visited my site today, he uses IE11 and Chrome on S6

[sabikeuk]

Problem still persist. It happened to me this time. I have cleared cache - same issue. Removed individual cookies - same issue. Cleared recent history - problem sorted.

Why is this happening and how can this be sorted for good ?

[GJC Web Design]

Very hard to know.. all my clients sites are now on J3.4.8 and not a single one has reported any problems...

the only dif with yours is.. 

I a using Virtuemarttemplates.net template and VP One page checkout

try with this switched off for a while..