$.widget is not a function Magento 2 fix

This issue is caused by multiple jquery instance, to fix it, just use the code below :

1. ADD : app/design/frontend/{Vendor}/{Theme}/requirejs-config.js

var config = {
     map: {
         '*': {
             'requirejs/require':  'requirejs/require'
         }
     }
 };

2. COPY lib/web/requirejs/require.js TO app/design/frontend/{Vendor}/{Theme}/web/requirejs/require.js

3. Line #1841 – 1885, change to :

if(moduleName!= 'jquery'){
	node.setAttribute('data-requirecontext', context.contextName);
	node.setAttribute('data-requiremodule', moduleName);
	//Set up load listener. Test attachEvent first because IE9 has
	//a subtle issue in its addEventListener and script onload firings
	//that do not match the behavior of all other browsers with
	//addEventListener support, which fire the onload event for a
	//script right after the script execution. See:
	//https://connect.microsoft.com/IE/feedback/details/648057/script-onload-event-is-not-fired-immediately-after-script-execution
	//UNFORTUNATELY Opera implements attachEvent but does not follow the script
	//script execution mode.

	if (node.attachEvent &&
	//Check if node.attachEvent is artificially added by custom script or
	//natively supported by browser
	//read https://github.com/jrburke/requirejs/issues/187
	//if we can NOT find [native code] then it must NOT natively supported.
	//in IE8, node.attachEvent does not have toString()
	//Note the test for "[native code" with no closing brace, see:
	//https://github.com/jrburke/requirejs/issues/273
	!(node.attachEvent.toString && node.attachEvent.toString().indexOf('[native code') < 0) && !isOpera) {
		//Probably IE. IE (at least 6-8) do not fire
		//script onload right after executing the script, so
		//we cannot tie the anonymous define call to a name.
		//However, IE reports the script as being in 'interactive'
		//readyState at the time of the define call.
		useInteractive = true;
		node.attachEvent('onreadystatechange', context.onScriptLoad);
		//It would be great to add an error handler here to catch
		//404s in IE9+. However, onreadystatechange will fire before
		//the error handler, so that does not help. If addEventListener
		//is used, then IE will fire error before load, but we cannot
		//use that pathway given the connect.microsoft.com issue
		//mentioned above about not doing the 'script execute,
		//then fire the script load event listener before execute
		//next script' that other browsers do.
		//Best hope: IE10 fixes the issues,
		//and then destroys all installs of IE 6-9.
		//node.attachEvent('onerror', context.onScriptError);
	} else {
		node.addEventListener('load', context.onScriptLoad, false);
		node.addEventListener('error', context.onScriptError, false);
	}
	node.src = url;
}

4. Clear all caches, deploy static content.

If this changes worked with you, please leave a comment 🙂