The most common cause for this error is simply that you have been logged out of your account because of the time that your account was idle. This is a security precaution for your protection. Simply log back into your account and you should be fine. Another reason maybe that your security settings are too high. The iHerb shopping cart does use cookies and if your security settings are too high, you may be blocking these cookies. All you need to do is adjust your security settings to allow cookies. For Internet Explorer, click on Tools, click on Internet Options, click on Privacy, and then adjust the settings to Medium.
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