[MPOS Technical Development]- Refactoring/Renaming of a CRT Entity in Extensions

If you decide to refactor or rename a Commerce Runtime (CRT) entity (lets say OldEntityName to NewEntityName) inheriting from CommerceEntity, one issue that I have faced is in Retail Server extension assembly the build fails with errors due to the RetailProxy classes relying on the definition of your old entity name.

Example of the error messages that you would see in this scenario are as follows-

Could not load type OldEntityName from assembly… and the command ‘bin\CommerceProxyGenerator.exe’ ..

Retail Proxy Error

The solution to this issue is a little tricky one. You need to compile the CRT data dlls keeping the OldEntityName in the References folder.

You need to then comment any reference to NewEntityName in the Retail Server Extension assembly. Then do a clean and a build of the solution.

If this succeeds with no errors, you can now go ahead to uncomment all references to NewEntityName in the Retail Server Extension assembly.

<Update>This article is based on 7.1 Retail SDK </Update>

-Hitesh Manglani






Custom error messages in MPOS

This post is for describing how we can show custom error messages in MPOS.

MPOS standard error handlers require that the strings to be shown as error messages are entered in the following format within the resources.json file (en-US).

“string_55001” : “This is a custom error.”,

Within MPOS we could use the following snippet to display any custom error messages

let displayMessageActivity: Commerce.Activities.DisplayMessageActivity = new Commerce.Activities.DisplayMessageActivity({
title: ‘Custom Error’,
message: Commerce.ViewModelAdapter.getResourceString(“string_55001“)
displayMessageActivity.execute().done(() => {
// code to run on successful display of the error dialog
}).fail(() => {
// code to run on failure in displaying the error dialog

If however the error condition is met in the Commerce Run Time (CRT) you need to show the error message in MPOS, you can leverage the CommerceRunTimeException

throw new CommerceException(“string_55047”, “CUSTOM ERROR MESSAGE”);


One possibility is that the error messages could be coming from a third party application. On a recent integration I received a list of predefined error codes with error messages from the application.I then defined an enum in the CRT which had the values as this status codes and names as the error messages




I defined a corresponding Enum in the CRT

public enum AppError




After deserializing the response I checked the ReturnStatus code from the application and used an offset (50050) to throw the correct error message from the resources.json file

if (Enum.IsDefined(typeof(AppError), res.ReturnStatus))
AppError err = (AppError)res.ReturnStatus;
throw new CommerceException(“string_” + (50050 + res.ReturnStatus) , err.ToString().Replace(“_”, ” “));

<Update>One thing you need to be aware is that the Error Status Code and Error Messages returned by the application should be constant. Any changes would mean that the MPOS package will need to be regenerated and redeployed.

I got following suggestion from my Mentor Mani (from Microsoft) for displaying the custom error messages- you can set custom properties in the response (CRT) and then parse the response in MPOS and show your message, you can also use extension properties and then parse it in MPOS. With this approach no need to define the error messages in resources.json.


Hope this helps

-Hitesh Manglani









MPOS, Retail Server – JSON API Integration

Recently I had to work on developing an integration between MPOS and a CRM application via Retail Server/CRT. The REST APIs provided where JSON based and I needed C# classes to deserialize the response.

My gut feel said that there should be a tool to do this and I need not create the required classes and properties manually.

Sure enough after some web search, I found https://jsonutils.com/

This is an awesome site where you can provide a sample JSON API response and get the C# classes that can be used to deserialize the JSON.

Hope this helps  you save some time, just as it helped me.

-Hitesh Manglani

Export X++ and Binary Hotfixes description from LCS

As it stands, I have spent quite some time painfully extracting X++ and Binary hotfixes description one at a time from LCS preparing release notes for my clients. This is because there is no feature in LCS (yet) which can allow export of this information.

If you are in the same boat, and you need to prepare release notes urgently, here is a tool by Tomek Melissa that you must try. Please note that its not a Microsoft supported release so you need to try it at your own risk.



PS: I have tried it and it works like a charm! Its not limited to just what I mentioned in this post.

-Hitesh Manglani


MPOS touch screen grid freeze issue

Note – This issue occurs only on few POS models so you may or may not face this issue. I do not have a list of models that have this issue, though I have experienced this on a HP RP9 POS and on D365FO 7.1 Retail SDK

When trying to scroll through MPOS using touch gesture, in the views that have a grid (examples Tender Declaration, Show Journal, Product Search) you may experience the screen layout on the row you touch, getting out of alignment with the remaining rows and the screen freezes with no further response to touch gestures.

A workaround is to use a mouse instead of touch for scrolling but obviously this can only be a temporary arrangement.

When we contacted Microsoft support, we were given a one line code change fix  that consists in changing the WinJS script that is provided  in the Retail SDK. The script to be changed is the WinJS ui.js and update the equivalent minified file (ui.min.js). The exact change can be seen in this github link: https://github.com/winjs/winjs/commit/a48a12e33e08fccdea7879af877b2cc3a7cb8ec3


-Hitesh Manglani


A process serving application pool ‘AOSService’ suffered a fatal communication error with the Windows Process Activation Service.

When trying to host the Demo VM in the company’s data centre (host) we came across the below error-

A process serving application pool ‘AOSService’ suffered a fatal communication error with the Windows Process Activation Service. The process id was ‘3680’. The data field contains the error number.

One thing I attempted to do, based on some suggestions on the web, was to “Enable 32-Bit applications” in the app pool.

This simply changed the error message to below-

Could not load file or assembly ‘Microsoft.Dynamics.AX.Security.SidGenerator’ or one of its dependencies. An attempt was made to load a program with an incorrect format.

I tried all the usual tools to try to troubleshoot the issue-Fiddler, Procmon, but no lead. Finally reached out to my mentor Brandon Ahmad . He was quick to point out to check the time zone on the Demo VM which may not be matching the host machine.

The demo VM was set on US Time Zone and the host was set to Singapore Time Zone, once I changed the timezone in the demo VM to match the host, that fixed the issue!


-Hitesh  Manglani

The significance of being in the zone, time zone that is.

This is a post with respect to how combined date/time fields is handled in AX/Dynamics 365 for Operations (Dyn365FO). For more information on the type of date and time fields in AX visit the following link from docs.microsoft.com.

Date/time data and time zones

Dyn365FO stores combined date/time fields internally in the SQL database based on UTC time zone. Whenever the date is to be displayed to the user, an offset based on the user preferred time zone is applied and then shown to the user.

This preferred time zone is set in the following section in Dyn365FO.

System Administration-> Users -> Users

User Options

Options-> Preferences

Time Zone

An excellent post that take a deeper dive on the subject along with the X++ code is found in the below link

Working with utcDateTime Functionality in Dynamics AX 2012 – StoneRidge Software


-Hitesh Manglani