If your organisation is still running a portal on Adxstudio, a legacy Dynamics 365 portal, or an early Power Apps portal build, there is a Microsoft-imposed change coming in June 2026 that will affect how your site behaves. It is not a rumour and it is not a marketing deadline — it is written into Microsoft’s official deprecations list on Learn. The good news is that with a few months of runway, planning a clean migration is entirely manageable. The less good news is that customers who wait until Q2 2026 to start planning will be scrambling.
This post covers what is actually changing, which portals are affected, and the practical steps we recommend for Dynamics 365 customers still on legacy infrastructure.
What you’ll learn:
- Which portal platforms are affected and what “deprecated” actually means
- The June 2026 change that will affect every existing portal — not just old ones
- A practical planning checklist for the next 6–9 months
- Where Power Pages fits as the migration target
- What to do first if you are still on Adxstudio
The three deprecation stories to know about
There is not one deprecation happening — there are three, and they overlap.
1. Adxstudio Portals. Microsoft ended support for Adxstudio some years ago. If you are still running it, the product technically works but you get no security patches, no compliance updates, and no help from Microsoft when something breaks. Many organisations have carried on regardless. That risk profile is getting harder to justify every quarter, and it becomes acute the moment you hit an audit, a customer security review, or a compliance question.
2. Legacy Dynamics 365 Portals (v8, v9 early versions). These have been progressively rolled into Power Pages. The Power Apps portals admin center was deprecated in June 2023 and is no longer available. Newly created portals now sit in the Power Pages admin hub. Portals created in Power Apps portals have shown up in Power Pages since October 2023. If you are still using the old admin surfaces, the writing has been on the wall for a while.
3. The June 2026 table permission enforcement. This is the one most teams have not planned for. Starting in June 2026, every Power Pages site will have table permissions enforced for all forms and lists, regardless of whether you have the “Enable Table Permissions” setting turned on. That is not a deprecation in the usual sense — it is a mandatory security change that applies to sites you have already built. Sites that were set up when table permissions were optional will need to be reviewed and reconfigured before the change lands, or forms and lists will start behaving differently for portal users.
Why the June 2026 change matters more than you think
Read that again. It applies to every site, new or existing. If a portal was originally built with “Enable Table Permissions” off — which was the historical default — the permission model is going to be enforced whether the site was configured for it or not.
In practice, we see two failure modes when this change lands on an unprepared portal:
- Portals go quiet. Lists and forms show no records because no table permission was ever configured to grant read access.
- Portals over-expose data. Someone applies Global access as a quick fix to unblock the empty portal, opening up records to users who should not see them.
Both are avoidable if the review is done in the months before the change. Neither is easily fixed under time pressure with users complaining.
If you have any existing Power Pages or legacy portal in production, the table permission review is the single most important thing on your 2026 roadmap for that site. Our Power Pages security guide walks through the web role and table permission model in detail — it is worth reading before you scope the review work.
Which portal are you on? A quick self-diagnosis
If you are not sure which platform your portal is running on, the fastest tells are:
- Adxstudio — the portal was set up before Microsoft’s acquisition of the product. You log into an on-premise admin surface. Support has ended.
- Legacy Dynamics 365 Portals — you access the site through the old Dynamics 365 portals admin center or an older Power Apps portals admin center. The URL structure often has references to portals rather than power pages.
- Power Apps Portals (mid-generation) — created in the 2020–2023 period, now surfaced through the Power Pages admin hub. Functional and supported, but built before Power Pages became the primary experience.
- Power Pages (current) — created after the Power Pages branding took over. Modern design studio, current admin experience, latest security defaults.
Any organisation still on the first two categories has migration work to do. The third category needs a review against the June 2026 change but does not necessarily need re-platforming.
What we recommend Dynamics customers do in the next 6–9 months
A structured plan looks something like this. Adjust for your own environment and the number of portals in play.
Step 1 — Inventory every portal you own
You may have more than you remember. Marketing sites, customer support portals, partner hubs, event registration sites, invoice portals, RFP portals, vendor onboarding sites. Get the list.
For each one, capture the platform (Adxstudio / legacy / Power Apps / Power Pages), the primary users, the tables the portal reads and writes, and the current state of table permissions.
Step 2 — Score the risk
Not every portal has the same exposure. Prioritise by three factors:
- Data sensitivity. Portals exposing financial, customer, or PII data get first attention.
- User count. More users = more failure surface.
- Business criticality. If the portal supports revenue-generating processes, it is a priority.
Step 3 — Review table permissions on every portal that will still be in production in June 2026
Even the ones that look fine today. The change applies to all sites. This is not optional homework. If a portal was set up with the enforce setting off, someone needs to look at each form and each list, decide the right access type (Contact, Account, Self, Parent, or Global), and configure it explicitly.
If you built the portal with a partner, this is exactly the kind of review work to bring them back in for.
Step 4 — Plan migrations off Adxstudio and legacy platforms
The only long-term supported target is Power Pages. Plan for:
- Rebuilding the site rather than lift-and-shifting. The data model layer stays largely the same, but the presentation layer is different enough that a rebuild is usually cleaner than a migration.
- Re-doing authentication properly. If you were still on Local Authentication for a customer portal, this is the moment to migrate to Azure AD B2C or Microsoft Entra External ID.
- Testing on modern browsers with modern security expectations. Old portals often break in ways nobody has noticed because nobody uses the affected features anymore.
Our Power Pages Templates guide covers the current template set — most modern portals now start from one of them rather than from scratch.
Step 5 — Rehearse the change before it goes live
If you are the admin on the portal, do a controlled test in a sandbox before June 2026. Turn on the enforce setting, see what breaks, fix it in the sandbox, and roll the fix to production. Then when the mandatory change lands, nothing changes for your users.
What does a portal migration actually look like?
The short answer: less painful than most teams expect, if the underlying Dataverse data model is clean.
The longer answer: expect four to eight weeks of work for a mid-complexity customer portal, and longer for a portal with heavy custom code, unusual integrations, or multi-language content. The work breaks into scoping, rebuild in a Power Pages environment, data model verification, permission and role configuration, integration re-testing, and user acceptance testing. If your portal involves payment processing, our Power Pages Authorize.Net integration guide covers the pattern we use most often for customer-facing payment flows.
Complex portals with custom pro-code components take longer. Portals with an active customer base need a careful cutover plan so users are not locked out mid-migration.
Frequently Asked Questions
Does the June 2026 change affect brand new Power Pages sites?
Any new site created recently already has table permissions enforced by default. The June 2026 change is aimed at older sites where the enforce setting is off. If your portal was set up in the last year or so, the enforce setting is probably already on — but confirm, do not assume.
Can we keep running Adxstudio if we have a perpetual licence?
Technically yes, the product still runs. There is no Microsoft support, no security patches, and no path to modern authentication providers. Most organisations that still have Adxstudio in production hit a compliance or security review question that forces the decision. It is better to move on your timeline than on a crisis timeline.
What is the target platform we should be migrating to?
Power Pages. It is Microsoft’s supported portal product, sits inside the Power Platform, and integrates natively with Dataverse, Microsoft Entra identity, and the rest of the Dynamics 365 stack. Custom React portals are also a valid choice for scenarios where Power Pages is the wrong fit — but they are the exception, not the default.
How long does a migration typically take?
Four to eight weeks for a mid-complexity customer portal on clean data. Longer for portals with custom pro-code components, heavy integrations, or messy data models underneath. The best predictor of migration timeline is the state of the underlying Dataverse — a well-modelled environment migrates fast, and a messy one does not.
What if we have already ignored the deprecations so far?
You have time, but not a lot of it. If you start planning this quarter, a migration off Adxstudio to Power Pages before June 2026 is achievable. If you wait until Q1 2026 to start, you will be looking at a rushed job with the enforcement change landing partway through. Start the inventory step now.
Conclusion
Microsoft’s portal deprecations are not a surprise. Adxstudio has been out of support for years, legacy portal admin centers have been retiring in stages, and the June 2026 table permission enforcement was announced well in advance. What catches teams out is not the deadline — it is realising in April 2026 that they have five portals and no plan.
The teams that come through this cleanly are the ones who start the inventory now, review permissions in the next quarter, and plan migrations across the next two to three quarters.
Still on Adxstudio or a legacy Dynamics 365 portal? MTC helps Dynamics 365 customers plan and deliver Power Pages migrations, including permission reviews for the June 2026 change. Explore our Power Pages services or email salesteam@mtccrm.com.
