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What Breaks the Most After Dynamics 365 Upgrade & How to Overcome Them?

Written by Avo Automation | Aug 26, 2025 6:50:50 AM

Microsoft Dynamics 365 (D365) is built to continuously evolve. With monthly patches and two major release waves each year, Microsoft introduces new capabilities, performance enhancements, and security improvements. While these updates are designed to keep your digital ecosystem modern and efficient, they often trigger unexpected disruptions, especially in environments that are heavily customized or deeply integrated. 

The question is no longer “Will something break?” but “What will break, and how badly?” 

In this article, we explore the most common areas of failure post-update, why they occur, and what you can do to minimize the impact. 

Customizations and Extensions: The Fragile Backbone 

Many organizations extend D365 functionality through custom workflows, plugins, Power Automate flows, JavaScript, and third-party apps. These extensions often depend on internal schema, form logic, or deprecated APIs. During updates, changes to these elements can cause custom code to behave unexpectedly or fail entirely. 

A common example involves custom JavaScript functions that rely on the DOM or unsupported form events. After an update, these scripts might no longer load or execute as intended, causing fields not to populate or validations to fail. Similarly, Power Automate flows may break if underlying data entities or triggers are modified or deprecated. 

The risk becomes especially acute in implementations where code overlays - rather than supported extensions - are used. Since overlays replace standard code, updates may overwrite or disable them altogether. 

Related Reading: Microsoft Dynamics 365 Testing Best Practices: Ensuring Success in the Digital Transformation Era

Integration Failures: When the Ecosystem Falls Out of Sync 

D365 rarely operates in isolation. It’s often integrated with ERP systems, customer portals, marketing platforms, analytics engines, and external databases. These integrations rely on APIs, webhooks, service endpoints, and authentication protocols—all of which can change without notice during an update. 

When Microsoft modifies service endpoints, alters security models (e.g., OAuth scopes or token lifetimes), or introduces schema changes in APIs, integration points begin to fail. This results in errors such as 401 unauthorized access, 500 internal server errors, or data mismatches across systems. 

Below is a snapshot of typical integration breakpoints: 

Integration Layer 

Typical Issue After Update 

Resolution Strategy 

REST APIs / Webhooks 

Endpoint not responding or schema mismatch 

Validate API contracts before and after updates 

Power Platform connectors 

Deprecated triggers or missing entities 

Monitor connector updates from Microsoft 

Authentication / OAuth 

Token failures or expired client secrets 

Refresh and re-test all auth credentials 

Middleware (e.g., ADF) 

Data pipeline failures or timeout errors 

Run full ETL cycle tests pre- and post-update 

 Related Reading: Is It Safe to Trust Automated Tests for Critical Interconnected D365 Modules? 

Role-Based Security: When Permissions Suddenly Disappear 

One of the more silent yet business-critical failures occurs in security roles. Microsoft occasionally introduces new permissions, modifies entity-level access, or resets configurations. As a result, users may suddenly find themselves locked out of records or unable to perform certain actions they had access to before. 

These issues are difficult to detect during the update process, since they often don't manifest until end users try to engage with specific modules. Business-critical workflows, such as case resolution or quote approvals, may halt unexpectedly due to insufficient access rights. 

A robust way to address this is by capturing and comparing permission matrices before and after each update cycle. Test automation tools that support security role validation can significantly reduce the overhead in identifying these subtle but critical changes. 

UI Customizations: Breaking the User Experience 

Model-driven apps are highly customizable, but that flexibility comes with risk. UI updates—such as Fluent UI changes, new command bars, or altered form rendering logic—can break custom scripts or cause inconsistent behavior across different devices and browsers. 

If your team has used JavaScript that manipulates form elements directly or applied unsupported CSS modifications, those customizations are likely to fail or cause layout issues. In extreme cases, users may not be able to interact with key UI elements, resulting in broken workflows or incorrect data entry. 

For stable customization, it’s advisable to use Microsoft-supported approaches like the Power Apps Component Framework (PCF). Unlike direct DOM manipulation, PCF offers a future-safe method of embedding custom components within D365 without being affected by internal UI changes. 

Test Automation and Manual Scripts: The Testing Bottleneck 

Testing is often the first and most visible casualty of a D365 update. Traditional test automation suites—especially those using Selenium, RSAT, or record-and-playback tools - tend to rely on brittle UI locators and hard-coded scripts. When form layouts, control IDs, or field names change, these tests fail en masse, even if the business logic remains intact. 

Manual test teams, already under pressure, may take days or weeks to validate regressions, delaying go/no-go decisions and potentially putting production environments at risk. 

Here’s a comparison of testing approaches and their resilience post-update: 

Test Method 

Resilience to D365 Updates 

Maintenance Overhead 

Time to Recover 

Manual Testing 

Low 

High 

Several Days 

RSAT 

Medium (only standard scenarios) 

Medium 

1–2 Days 

Selenium-based Scripts 

Low (UI-dependent) 

High 

3–5 Days 

Avo Assure (No-Code AI) 

High (self-healing tests) 

Low 

Few Hours 

Intelligent, no-code testing tools like Avo Assure offer a more resilient alternative. With features like smart locators, reusable test modules, and automatic test healing, these platforms adapt to UI and functional changes without requiring script rework. 

Business Process Flows: When Guided Journeys Collapse 

Business Process Flows (BPFs) are essential for enforcing process consistency across sales, service, and operational workflows. However, BPFs are sensitive to entity schema changes, field-level updates, and logic shifts—all of which are common during D365 releases. 

When BPFs break, users may be unable to move to the next stage in the process, or the BPF may not trigger at all. This leads to bottlenecks, failed escalations, and inaccurate reporting. 

Preventing this requires thorough validation of BPF logic and transitions as part of the regression testing plan. Testing should include real-world scenarios and multiple user roles to ensure each stage behaves as expected. 

Related Reading: What’s End-to-End (E2E) Testing? Significance, Stories & Best Practices for Building Software That Works

Conclusion: Preparing for What Breaks 

Every D365 update introduces a balance of value and risk. While Microsoft provides detailed release notes and previews, many issues go undetected until after deployment. Understanding what typically breaks - custom code, integrations, security roles, UI elements, test suites, and process flows - helps QA and IT teams focus their validation efforts more effectively. 

The most forward-thinking teams treat updates not as disruptions but as opportunities to modernize their testing strategy. This includes moving away from brittle, manual methods and embracing intelligent, scalable solutions that match D365’s pace of change. We have created just the right checklists for modern enterprises to ensure a smooth D365 upgrade

By applying these checklists during a real-time D365 upgrade, updates can become routine rather than risky, and QA can finally move from a bottleneck to a business enabler. 

Testing Microsoft Dynamics 365 is a complex but rewarding endeavor. By following these best practices, you can ensure a smooth implementation, minimize risks, and maximize ROI. Remember, testing aims not only to find bugs but also to deliver a system that empowers your business and drives growth.

Check out Avo Assure for Dynamics 365 Testing to experience seamless MD365 testing that will accelerate your enterprise-grade MD365 testing.

As you embark on your Dynamics 365 journey, keep this quote in mind: “Quality is not an act; it is a habit.” – Aristotle. Make testing a habit, and success will follow.