Unable to download from Marketplace

Question

Unable to download from Marketplace

Alex Vergo 5

I have been attempting to download the Claude for word/microsoft 365 add from Marketplace for about 2 days now, but have been met constantly with the following error message:

{"Message":"Internal Server Error","ErrorMessage":"Unable to read RPS data encryption certificate","RequestId":"[Moderator Note: Personal Info Removed]","Suggestion":"For local debugging, set ASPNETCORE_ENVIRONMENT environment variable to \u0027Development\u0027 and restart the application"}

{ "Message": "Internal Server Error", "ErrorMessage": "Unable to read RPS data encryption certificate", "RequestId": "[Moderator Note: Personal Info Removed]", "Suggestion": "For local debugging, set ASPNETCORE_ENVIRONMENT environment variable to 'Development' and restart the application"

Is this a local problem to my computer, or a more global problem coming from Microsoft's servers? I haven't seen anything online about it.

Fabian Jäger 0 Reputation points

2026-07-26T06:31:55.35+00:00

Some users reported that they experienced the same error message when trying to install the Mailbutler add-in from the marketplace: https://marketplace.microsoft.com/en-us/product/office/WA200001031
Chloe-V 11,275 Reputation points Microsoft External Staff Moderator

2026-07-27T06:10:42.6133333+00:00

Thank you, Fabian Jäger, for confirming that other users are experiencing the same error. I appreciate the information and will continue to monitor for updates.

1 answer

Your answer

Fabian Jäger 0 Reputation points

2026-07-26T06:31:55.35+00:00

Some users reported that they experienced the same error message when trying to install the Mailbutler add-in from the marketplace: https://marketplace.microsoft.com/en-us/product/office/WA200001031
Chloe-V 11,275 Reputation points Microsoft External Staff Moderator

2026-07-27T06:10:42.6133333+00:00

Thank you, Fabian Jäger, for confirming that other users are experiencing the same error. I appreciate the information and will continue to monitor for updates.

Answer 1

Chloe-V 11,275 Microsoft External Staff Moderator

Hi Alex Vergo,

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.

I understand how frustrating it is to encounter an “Internal Server Error” when trying to download the Claude add-in for Word/Microsoft 365.

The message “Unable to read RPS data encryption certificate” indicates a server-side problem with the Microsoft Marketplace or add-in service rather than a problem with your computer. The suggestion to set ASPNETCORE_ENVIRONMENT to Development is intended for service developers, so please do not make this change on your device.

Please try searching for and installing the newer Claude for Microsoft 365 add-in instead of the separate Claude for Word add-in. You can also retry from Word for the web or a private browser window.

If the same message continues, please contact Microsoft Support and provide both Request IDs shown in the message, as these can help trace the server requests.

Please note that this is a user-to-user support forum. Moderators, contributors including external Microsoft employees cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas only.

Thank you for your understanding.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Alex Vergo 5 Reputation points

2026-07-25T17:14:46.2666667+00:00

I am still plagued by this issue from all fronts while trying to download ANY add-in to word. I have claude installed as an add-in on excel and powerpoint with no issues. I attempted to use it on word about a week ago, and was met with a "old version, needs to be deleted and updated" message directly in the add-in. So i removed it from Word, and have not been able to get it back on since. I've tried contacting MS support, but their support page is horrendous, and I cannot type more than 10 words into the generic support search bar, and cannot locate a "chat with a live rep" section anywhere.
Chloe-V 11,275 Reputation points Microsoft External Staff Moderator

2026-07-25T23:59:41.38+00:00
Hi Alex Vergo,

Thank you for the update. I’m sorry this incident is now affecting all Word add-ins.

Since the incident persists, please contact Microsoft Support via live chat:

Go to Microsoft Contact Us.

Click Show expanded list of products.

Select Word > Get Home support.

Type live chat, then select Get Help > Contact Support.

Sign in with the affected account, or use another Microsoft account if necessary.

Select Microsoft 365 and Office > Technical support.

Choose Chat with a support agent in your web browser.

Please note that this is a user-to-user support forum. Moderators, contributors including external Microsoft employees cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas only.

Thank you for your understanding.