How To Fix “cannot decode raw data” (NSURLErrorDomain:-1015) WordPress Error.

I recently received a frantic email from a customer alerting me that their WordPress website had been hacked.

Of course, I always check to see if what the customer states is true before I jump in the boat or begin the fire drill to make everything like it once was.

What struck me as odd was that when I opened and read the email, I could easily open a Chrome web browser and load the customer’s website.

I responded to the customer’s email, informing the customer I could access the website without issue. I requested the customer to send me screenshots of what they were seeing.

A few moments passed, but sure enough, the customer sent screenshots of their website loaded in a browser and displaying Chinese text.

Seeing the customer using the Firefox web browser, I, too, opened a Firefox web browser only to discover that the website loaded to an all-white screen.

I opened the web browser’s Developer Tools and was able to see the website was resolving and loading with a 200-request response.

What on earth could be causing this “kiss of death” white screen for this WordPress website?

The first fix I tried was removing and re-creating a .htaccess file via the Bluehost File Manager — no success, still a white screen of death.

I then searched for the last updated or modified files sorted in descending order by modified date — no success, still a white screen of death.

I then searched error log files for roughly 30 minutes and found nothing out of the normal or ordinary that might raise an eyebrow.

After all, why would the website load in one browser and not another?

To be certain, I attempted to load the website using Safari. To my surprise, the website didn’t load but gave me more information to work with than Firefox: “cannot decode raw data” (NSURLErrorDomain:-1015).

What is causing the “cannot decode raw data” (NSURLErrorDomain:-1015)?

I had never seen such an error before in my life. So, I Googled it, but nothing appeared to be up to date or relevant to my situation.

When in doubt and with all my experience working in WordPress, I made the next best move: disabling plugins one at a time.

Oftentimes, when websites run 5 or more WordPress plugins and plugins are not updated regularly, there is a high chance that WordPress plugins may conflict with one another, if not WordPress in general.

This customer had 28 WordPress plugins installed, with 20 active. I always advise customers to delete deactivated WordPress plugins when not using them to keep conflicts from occurring.

Nevertheless, I reviewed each plugin before I started blindly disabling it in hopes of remedying the error.

One of the many things I’ve learned managing hundreds of WordPress websites over the years, whether at WPEngine, GoDaddy, Bluehost, or Hostgator, is always starting with troubleshooting security or cache plugins.

WordPress security and cache plugins often are the culprit of such errors. In this case, this customer’s website didn’t have a security plugin but was using WP Super Cache.

After I updated the WP Super Cache plugin and cleared all cached pages, I tried loading the website with no success.

It wasn’t until I disabled the WP Super Cache plugin that the website was able to load across all browsers, remedying the “cannot decode raw data” (NSURLErrorDomain:-1015) error that caused the white screen of death.

Oddly enough, I was able to re-activate the WP Super Cache plugin without any other loading issues to the website across all web browsers. Strange if you ask me.

You may or may not use the WP Super Cache plugin, but I would certainly start with security and cache plugins should you encounter the same issue for your WordPress website.

All is well, and the customer is happy to resume business as usual. Let me know if you have questions or comments.

That’s all for now!