Error with "option" translation on order confirmation email
I have a multistore in different languages. I've found an error that cannot solve.
When the customer receives an order confirmation email, the word "option" for the different product otions (blue, green, yellow...) sometimes has the translation of the wrong language. For example, in the english store it appears in spanish, for the french store it is in portuguese, etc.
This happens often, but not always. For example during 3-4 days, 50% of the orders have this problem. Then again after 2-3 months.
I've checked and everything seems correct, every language has its correct translation for this word.