URGENT :: PostUrl has been broken by a platform change as of today

URGENT :: PostUrl has been broken by a platform change as of today

In our app we rely heavily on the PostUrl function to call various third party APIs to generate emails and SMSes to clients, among other things.

As of today this function has suddenly broken which is having a serious impact on our small business

This must be a platform issue as I have not changed the relevant script in our app.

The format I use is as follows:
  1. the_response = postUrl(url, json, headers,false);
The error generated (as of today) is:

Execution Failed
Error details:
Error in executing sendMessage workflow.
Error.
Error in executing Set Variable task. Unable to update template variable the_response.
Error evaluating MAP expression :
Return Value:
null

Please fix and advise urgently.

Anton