We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Unable to load website if any background XHR request is failed

more options

I am using Firefox Developer Edition Version: 110.0b5 (64-bit) on M1 Mac running Ventura 13.1.

I am building an webapp some XHR triggering in background but it is not necessary to run the application (running fine on other browsers). But on Firefox Developer Edition, It shows a error window with the message and stops loading the application.

Firefox can’t establish a connection to the server at localhost:4000.

localhost:4000 is the failing XHR request domain. I have attached the screenshot.

How to ignore the XHR failing errors just like other browsers?

I am using '''Firefox Developer Edition''' Version: 1'''10.0b5 (64-bit)''' on '''M1 Mac''' running '''Ventura 13.1'''. I am building an webapp some XHR triggering in background but it is '''not necessary''' to run the application (running fine on other browsers). But on '''Firefox Developer Edition''', It shows a error window with the message and stops loading the application. '''Firefox can’t establish a connection to the server at localhost:4000.''' ''localhost:4000'' is the failing XHR request domain. I have attached the screenshot. How to ignore the XHR failing errors just like other browsers?
Attached screenshots

Chosen solution

It is resolved. Actually, It's a iFrame, The error appears inside the iframe that looks like an browser alert.

Read this answer in context 👍 0

All Replies (1)

more options

Chosen Solution

It is resolved. Actually, It's a iFrame, The error appears inside the iframe that looks like an browser alert.