OMEX Add-in Store returns HTTP 500 for account across devices. Possible entitlement/regional provisioning issue.

Toon Budeners 0 Reputation points
2026-09-09T07:40:47.1533333+00:00

Hello,

I am looking for assistance from Microsoft or the OMEX (Office Add-ins Store) team regarding what appears to be an account-level issue affecting the Excel Add-ins Store.

The problem began around 8 September and now affects multiple devices.

Issue

The Excel Add-ins Store fails to load and returns:

500 Internal Server Error

API endpoint:

api.addins.omex.office.net/api/addins/search

Response:

Code: InternalServerError Description: Could not serve request because of an internal failure

The error occurs even when requesting the default catalogue with no search term, so it does not appear to be related to any specific add-in.

Symptoms

  • The EVE Online Excel add-in previously worked correctly.
  • The add-in stopped working on my laptop and displayed "This add-in could not be started."
  • After removing it, I could no longer reinstall it.
  • The Add-ins Store itself now fails to load.
  • The problem affects both computers using the same Microsoft account.

Environment

  • Microsoft 365 Personal
  • Windows 11
  • Same Microsoft account on both devices
  • Microsoft Edge and Edge InPrivate
  • Multiple network connections tested

Troubleshooting Already Completed

I reproduced the problem using:

  • Netherlands catalogue (ad=NL)
  • Belgian catalogue (ad=BE)
  • Dutch locale
  • English locale
  • Two separate Windows 11 computers
  • Edge and Edge InPrivate
  • Home internet connection
  • Mobile hotspot

Other Microsoft services and Microsoft Store functions work normally. Only the OMEX Add-ins Store search endpoint returns HTTP 500.

Account and Licensing Information

  • Microsoft 365 Personal purchased directly from Microsoft.
  • Account region is Belgium.
  • Subscription is billed in EUR with Belgian VAT.
  • A previous renewal attempt generated the error: ConvBlockCurrencyCountryMismatch.
  • Add-in Store requests nevertheless appear to default to the Netherlands catalogue in some cases.
  • vnextdiag.ps1 confirms both devices are licensed with the same O365HomePremRetail subscription.
  • New Microsoft 365 licence tokens were issued on 8 September.
  • One device still shows a provisioned ProPlus2021Retail entitlement from a previous Office Professional Plus 2021 installation.
  • The other device has no Office 2021 entitlement.

Correlation IDs

Initial Correlation ID: [PII removed]

Service Fabric Request ID: [PII removed]

Belgian Catalogue Correlation: [PII removed]

English Locale Correlation: [PII removed]

Questions

  1. Has anyone seen OMEX return HTTP 500 consistently for a single Microsoft account?
  2. Could this indicate corrupted Add-ins Store entitlements or failed marketplace provisioning?
  3. Could the earlier ConvBlockCurrencyCountryMismatch error indicate inconsistent regional metadata between Microsoft 365 licensing and OMEX services?
  4. Is there a way to have my account's OMEX/Add-ins Store provisioning reviewed or reset?
  5. Could the EVE Online add-in entitlement be restored if the account is reprovisioned?

I can provide screenshots, response headers, HAR traces, licensing diagnostics and additional logs if required.

Kind regards,

Toon Budeners

Microsoft 365 and Office | Excel | For home | Windows
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1 answer

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  1. Kai-H 26,135 Reputation points Microsoft External Staff Moderator
    2026-09-09T12:51:11.1733333+00:00

    (Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.)

    Hi, Toon Budeners

    The consistent HTTP 500 response across two devices, browsers, networks, and catalogs points to an OMEX service-side failure rather than a damaged Office installation. Current service telemetry also shows broader OMEX Add-ins Store search and entitlement failures, so the regional and old Office 2021 entries may be unrelated.

    Here are some suggestions you can try:

    Avoid reinstalling Office or changing more license settings for now, since both devices reach the same failing server endpoint.

    Wait several hours and test Home > Add-ins > More Add-ins again. Also check the Office Add-ins known issues page.

    If the HTTP 500 continues, open the Windows Get Help app, enter “Microsoft 365 Excel Add-ins Store HTTP 500,” and select Contact Support. Personal subscription users can request chat or a callback from there.

    Provide the correlation IDs, exact UTC timestamps, HAR trace, and the affected account region. Ask that the case be escalated to the Office Store/OMEX service team for entitlement and marketplace provisioning review.

    If the EVE Online entitlement is missing after service recovery, include its Marketplace listing details in the same support case.

    Please be advised that this is a user-to-user support forum. Moderators and contributors, including external Microsoft employees, are not allowed to directly interfere with Microsoft product features or access back-end systems. Our role is limited solely to providing technical guidance on reported incidents, requests, or ideas.   

    Thank you for your patience in reading, I hope this information has been helpful to you. 

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