Ordered some new checks from Costco as a "guest" since I haven't set up an online account (generally speaking, I wouldn't use, but to order checks, I need to do it online… (閱讀更多)
Ordered some new checks from Costco as a "guest" since I haven't set up an online account (generally speaking, I wouldn't use, but to order checks, I need to do it online - not in the store). I put my full order together in the cart, went through the full process of completing the order and payment, but after submitting, I expected the order confirmation page. However, I received the notice that the Harland Clarke check printing vendor site won't allow firefox to display the page. Without that confirmation page, I don't have an order number to reference. The instructions provided says to embed the link (which link?) in another tab to open the missing page. I've also tried following all other instructions; going on the Mozilla/Firefox desktop/ trying to find a Mozilla contact phone number, etc. All that happens is that I go into a never-ending circle - which means no-where. What am I missing? This is what I get:
Fix error “Website will not allow Firefox to display the page.”
3–4 minutes
Firefox, Firefox for Android Firefox, Firefox for Android Last updated: 8/24/25 36% of users voted this helpful
Some websites don’t allow their content to appear inside another website. If a site tries to embed a page that blocks this, Firefox will show an error that it cannot open the page:
“To protect your security, [website] will not allow Firefox to display the page if another site has embedded it.”
This is a security feature on the website being embedded. It prevents clickjacking, where a site tries to load another site without permission, often to trick users into clicking something they didn’t intend.
This error is not caused by Firefox. It’s a choice made by the website owner.
Why does this happen?
Websites can control how their content is used. They may block it from being shown inside another site using special security settings like:
X-Frame options headers
Content security policy rules
These settings are common for banking sites, schools, government services and others that need tight security.
What can I do?
You can still view the blocked content by opening it directly.
On desktop
Right-click the link or embedded area.
Select Open Link in New Tab or Open Link in New Window.
If you can’t right-click, try copying the link (long-press on Mac trackpads) and pasting it into a new tab.
Tip: You can also drag the link into a new tab if using Firefox on desktop.
On mobile (phone or tablet)
Tap and hold the link or embedded area (where the content should appear).
Choose Open in New Tab from the menu.
If that doesn’t work, try copying the link (if visible) and pasting it into a new tab manually.
Warning: On mobile, this may be harder to do if the embedded content doesn’t show clearly. Look for a blank or gray box on the page.
What if I need to use the original page?
Sometimes the website that’s embedding the content depends on that embedded page to work properly (for example, a school login system or internal portal).
If that’s the case:
Try opening the embedded page directly (as described above).
If that doesn’t help, you may need to contact the site owner and explain the issue.
Need help understanding this error?
If you're unsure what the page is trying to load or can’t figure out where to click:
Look for a blank box or missing content; that’s likely where the blocked page should appear.
If you're on mobile, try rotating your device or zooming out to better view hidden content.
Still stuck? Copy the page link and share it with your IT support, teacher or website admin.
Related articles
Firefox is stuck in Troubleshoot Mode
Websites look wrong or appear differently than they should
Site Permissions panel
These fine people helped write this article:
