WKWebView question

Hi,

I am using WKWebView to load and display the content of a web site. After the app was launched and running, the delegate method -webView:didFailNavigation:withError: got called. Following is the error description (error.description) extracted from this delegate method using Xcode debugger:

Error Domain=NSURLErrorDomain Code=-999 "(null)" UserInfo={NSErrorFailingURLStringKey=https://xxx.xxx.xxx/, NSErrorFailingURLKey=https://xxx.xxx.xxx/, _WKRecoveryAttempterErrorKey=<WKReloadFrameErrorRecoveryAttempter: 0x604000225fc0>}

I did some Google sessrch and found that Code=

-999

is caused by ErrorCancelled,
meaning: another request is made before the previous request is completed.

My question is: how to fix this issue in my app? Thanks a lot in advance.