Resource not found for the segment - Error while Invoking Action in MS CRM

Verify the following

• Confirm if action are in in Activated State, under Settings -> Process.
• Name of the actions are case-sensitive, including the prefix name.
• Must present and in default customization.
• Calling of a Global and Entity Specific action is different, refer the code below for a reference.

Calling of Global Action

function CallGlobalCustomAction(){

//get the current organization name

var serverURL = Xrm.Page.context.getClientUrl();

//query to send the request to the global Action

var actionName = "new_MyCustomAction"; // Global Action Unique Name - Also Case Sensitive

//set the current loggedin userid in to _inputParameter of the

var InputParameterValue = Xrm.Page.context.getUserId();

//Pass the input parameters of action

var data = {

    "MyInputParameter": InputParameterValue

};

//Create the HttpRequestObject to send WEB API Request

var req = new XMLHttpRequest();

//Post the WEB API Request 

req.open("POST", serverURL + "/api/data/v8.0/" + actionName, true);

req.setRequestHeader("Accept", "application/json");

req.setRequestHeader("Content-Type", "application/json; charset=utf-8");

req.setRequestHeader("OData-MaxVersion", "4.0");

req.setRequestHeader("OData-Version", "4.0");

req.onreadystatechange = function () {

    if (this.readyState == 4 /* complete */) {

        req.onreadystatechange = null;

        if (this.status == 200 || this.status == 204) {

            alert("Action Executed Successfully...");

            //You can get the output parameter of the action with name as given below

            result = JSON.parse(this.response);

            alert(result.MyOutputParameter);

        }

        else {

            var error = JSON.parse(this.response).error;

            alert("Error in Action: " + error.message);

        }

    }

};

//Execute request passing the input parameter of the action 

req.send(window.JSON.stringify(data));

}

Calling of Entity Specific Action

function ExecuteEntitySpecificAction(entityName, entityId, actionName) {

debugger;

var serverURL = Xrm.Page.context.getClientUrl();

var query = entityName + "(" + entityId + ")/Microsoft.Dynamics.CRM." + actionName;

var req = new XMLHttpRequest();

req.open("POST", serverURL + "/api/data/v8.2/" + query, false);

req.setRequestHeader("Accept", "application/json");

req.setRequestHeader("Content-Type", "application/json; charset=utf-8");

req.setRequestHeader("OData-MaxVersion", "4.0");

req.setRequestHeader("OData-Version", "4.0");

req.onreadystatechange = function () {

    if (this.readyState == 4 /* complete */) {

        req.onreadystatechange = null;

        if (this.status == 200) {

            var data = JSON.parse(this.response);

            if (data != null)

                if (data.Result == "True") {

                    alert("Duplicate Quote created...");

                    var windowOptions = {

                        openInNewWindow: true

                    };

                    Xrm.Utility.openEntityForm("quote", data.DuplicateQuoteId, null, windowOptions);

                }

                else

                    alert("Something went wrong while copying Quote. Error: " + data.Result);

        } else {

            var error = JSON.parse(this.response).error;

            alert(error.message);

        }

    }

};

req.send();

}

The calling mechanism can be further simplified for calling custom actions by using Process.js and can be found here. This library simplifies calling custom actions from JavaScript.  Calling custom actions involves creating rather lengthy XML Http Requests and this library simplifies that down to a function call with a couple of parameters.  It also provides callbacks for success and errors.