Function json_last_error_msg() is not compatible with those in PHP 5.5

[upsell]

Function json_last_error_msg() returns "No Error" if no error has occurred but should null as is in PHP 5.5 version of this function.

[TobiasBg]

Thanks a lot for your report, upsell!

According to the ​PHP Documentation, json_last_error_msg() returns the string "No error" if there was no error, just as the compatibility function in WordPress does.

Can you therefore maybe clarify what you mean with "should null" here? Thanks!

[upsell]

You are right. I've used old version of:
​https://github.com/GetResponse/DevZone/blob/master/API/lib/jsonRPCClient.php
where no error returned null.

My mistake.