Share via

SharePoint Online classic master page – removed PrivacyLinkControl (v14.0) reference but users still getting assembly load error

VL, Shaik Aslam Farooq Baba 0 Reputation points
2026-05-29T03:37:06.8+00:00

Hello Experts,

I am facing an issue in a SharePoint Online classic publishing site with a customized master page, where users are encountering a page load failure due to a legacy assembly reference.

User's image

We found the below reference in the classic master page:
<%@ Register TagPrefix="microsoftonline" Namespace="Microsoft.Online.SharePoint.WebControls" Assembly="Microsoft.Online.SharePoint.PrivacyLinkControl, Version=14.0.0.0, Culture=neutral, PublicKeyToken=[Moderator note: personal info removed] " %>

This is a SharePoint 2010 (v14) assembly reference which is not supported in SharePoint Online.
Current Situation

  • Issue is resolved for some users
  • Still persists for other users (internal and external)

Affected users continue to see the same error referencing Version 14.0

Action Taken

  • Removed the above Version 14.0 PrivacyLinkControl reference
  • Re-uploaded and applied the updated master page

Assistance Required

Looking for guidance on:

  1. How to completely eliminate legacy (v14) references across the site
  2. Any approach to handle user-specific caching issues
  3. Best way to identify any remaining dependency causing this error

Microsoft 365 and Office | SharePoint | Development

2 answers

Sort by: Most helpful
Most helpful Newest Oldest
  1. Dora-T 13,745 Reputation points Microsoft External Staff Moderator
    2026-05-29T05:54:06.8266667+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 VL, Shaik Aslam Farooq Baba

    Thank you for reaching out to the Microsoft Q&A Forum and for sharing your issue.

    Please understand that this is a public-to-community forum. While moderators and community members can share guidance and experiences, we do not have access to internal diagnostics or backend systems required for deeper investigation.

    I have done some research but was unable to find any publicly available information that explains this behavior. Therefore, I recommend raising a support ticket with the Microsoft Support team so they can assist you further with a more in-depth analysis.

    Additionally, you may consider posting your question in on the Microsoft Community Hub or on GitHub, where engineers and experienced contributors can provide more targeted insights.

    I understand this may not be the answer you were hoping for, and I appreciate 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. 

    Was this answer helpful?

    0 comments

  2. AI answer

    2026-05-29T03:37:32.9133333+00:00

    In a classic SharePoint Online publishing site, this type of error is almost always caused by:

    • A remaining custom master page or page layout that still contains the legacy control/assembly reference, or
    • A page that is still using an older version of the master page (or a customized copy) even though the gallery copy has been updated.

    Because classic master pages and page layouts are cached and can be customized per page, the behavior can appear user‑specific.

    Use the following steps to eliminate the legacy reference and clear out page‑level issues.

    1. Verify all master pages and page layouts
    2. In the site collection, open the Master Page Gallery (/_catalogs/masterpage).
    3. Check every custom master page and page layout for any Microsoft.Online.SharePoint.PrivacyLinkControl or Version=14.0.0.0 reference, not just the one currently set as the default.
    4. Remove the reference from every file that contains it and re‑publish/approve the updated files.
    5. Ensure the site is using a supported master page:
      • For classic sites, prefer an out‑of‑box master page or a minimal/custom master page created with Design Manager. For minimal/custom master pages, ensure they only use supported controls. See the guidance in “Create a minimal master page in SharePoint” and “Convert an .html file into a master page in SharePoint.”
    6. Reset pages that may have customized master references

    If any publishing pages were directly edited or customized, they may still reference an older master or inline control.

    1. For pages that fail to load, use the Web Part maintenance or page edit options where possible and reset them to the default version. The troubleshooting guidance notes that when a page or master page has unsupported controls, resetting to the default version or removing the custom files resolves rendering errors.
    2. If custom content disappears after reset, re‑add it using layouts that do not depend on the removed control or on different Web Part zone layouts.
    3. Address user‑specific caching behavior

    The error persisting for some users but not others is typically due to:

    • Browser cache still holding the old master/page markup.
    • A page that a subset of users land on (home page, custom landing page, or a specific publishing page) still using the old master.

    Actions:

    1. Ask affected users to clear browser cache for the SharePoint domain and then reload the site.
    2. Confirm that the URL they are using is the same as the one that works for other users (no old bookmarks to a different page that still uses the legacy master).
    3. If the issue only occurs on specific pages, reset those pages as described above.
    4. Identify remaining dependencies

    To find any remaining references:

    1. In the Master Page Gallery and Pages library, download the .master, .html, and .aspx files and search their contents for:
      • Microsoft.Online.SharePoint.PrivacyLinkControl
      • Version=14.0.0.0
    2. Remove any occurrences, re‑upload, publish, and approve.
    3. If after upgrade or changes the site does not render and shows an “unexpected error” with a correlation ID, the documented cause is custom branding using custom master pages and content placeholders. In that case, switch temporarily to an out‑of‑box master page to confirm the problem is in the custom master, then fix or replace it.
    4. Long‑term recommendation

    Custom master pages in SharePoint Online classic are considered legacy and increase the risk of exactly these kinds of issues after platform changes or upgrades. The guidance recommends:

    • Avoiding custom master pages where possible and using themes, composed looks, and alternate CSS instead.
    • If custom master pages are kept, be prepared to update them whenever Microsoft 365 applies major functional updates.

    If the error persists after all custom master pages and page layouts are cleaned and pages reset, switch the site temporarily to an out‑of‑box master page. If the problem disappears, the remaining issue is in the custom master/page layout set; if it does not, open a support case with Microsoft for further investigation.

    References:

    AI-generated content may be incorrect. Read our transparency notes for more information.

    Was this answer helpful?

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.