Why did my customer get the error "Your session has timed out" when making a payment?

If the system times out in fewer than five minutes, the cause may be the loss of a secure connection. This usually occurs due to: 

• Internet traffic
• Browser cookies or cache
• Use of frames on your website

Internet traffic
Ensure the network you are using is not maxed out with its current allowed bandwidth. Disconnect internet enabled devices or applications consuming the most bandwidth and reattempt.

Browser cookies or cache
Your computer stores copies of frequently accessed pages in its memory cache or disk cache. If these become corrupt, the PayPal page may display differently and result in longer loading or browser closing times. You can find instructions for clearing the cookies and cache from your computer in your browser's Help menu.

Use of frames
Using frames on your website can also cause timeout errors. Using PayPal logos in frames prevents browsers from displaying the PayPal URL and security lock. PayPal doesn't allow its payment pages to be displayed inside a frame, because this can also cause run time errors for most browsers (if JavaScript is used on the website), or timeout issues when frames are used with payment buttons.

If using frames, add target="paypal" in the  <form action> tag of the HTML code to prevent our payment page from being displayed in a frame. For example, if your webpage uses framing, the first line of code in your PayPal button should look like this:  

<form target="paypal" action="https://www.paypal.com/cgi-bin/webscr" method="post">

Linking to a payment session instead of using a payment button or payment link can also cause session timeouts. If the code you're linking to looks like the following example, replace it with the HTML code provided to you in your saved buttons.