Web parts error message for guest users

[marioalcalde]

Hi everyone, I'm currently having some issues with SharePoint site web parts for guest users. Below is the description of the problem, and I'm attaching a screenshot as well.

Context

A modern SharePoint Team Site has been created with several pages and web parts in them (i.e.: Hero, News, Quick Links, Link, People, Forms, etc). The site's main purpose is to allow external users to navigate through it. The users are added as guests in Office 365 tenant and added into an Office 365 group which has Contribute access to the SharePoint site.

Problem

When I access as a guest user and navigate through the SharePoint site, most of the web parts in the pages show an error message instead of showing the web part content. This is temporarily fixed if I refresh the page, but the error keeps coming back randomly across the whole site where ever there's a web part.

Looking forward to hearing some comments or if someone has seen this before.

Best regards,

Mario

[#2]

Wow,
I'm not aware of any requirements those WebParts might have in regards of Guests users...unfortunately we cannot provide much help with the issue you are having here. It's clear to me the WebParts should work for Guests users with no problems

[#3]

@jcgonzalezmartin Hi Juan Carlos, thanks heaps for your response. I totally agree, specially if the site was built with 100% OOTB components.

I hope someone has any idea of why is this caused. In parallel I raised a ticket with MS to see if they can provide some feedback about it.

In the meantime I'll replicate the site in another O365 tenant and see if the error happens there too.

Best regards,

Mario

[#4]

We have the same error messages on our tenant. They only appear for guest users, especially with planner-webpart and activity-webpart.

[#5]

Update: The issue is still happening for all guest users in any browser. I've contacted a MS agent and I'll meet briefly.

I've replicated the whole Sharepoint site in a different tenant and the issue with the webparts doesn't occur for guest users. The only difference between one site and the other is that the one with the bug is with E3 license and the one without the bug is under Business Standard license.

I'll update the post after my meeting with MS.

Cheers,

Mario

[#6 · Accepted solution]

Update:
After my case was escalated to the SharePoint tech team in Microsoft, they discovered that there was a customised script added at the tenant level, stored in a sharepoint site called CDN. This site was created to store the script files after activating Office 365 CDN for the whole tenant and that way implement the Tenant Wide Deployment option for SharePoint Framework (SPFx) Extensions, which allows the use of the scripts.

For some reason the above is messing with the way guest users see web-parts and generating the bug.
The possible solutions Microsoft presented are two:
1. Remove the customised script (after assessing the impact that this removal may have in other sites in the tenant)
2. Grant read-only access to the guest users to the CDN sharepoint site where the scripts are stored

In our case, because we still need the scripts as they are part of a previous implementation that is currently being used, we decided to go with option 2.

I've tested adding a guest user to a group with read-only access to the CDN site where the scripts are, and now the guest user doesn't experience the bugs anymore.

Hope the above helps, and if you have any questions just flick me a reply.

Regards,
Mario

[#7]

Hi @marioalcalde
I have what seems to be this exact same issue. Could you please let me know where you found the CDN site? Or would this be different from tenant to tenant?

Thanks in advance!

[#8]

@marioalcalde I can replicate this issue. I am applying site scripts during the site creation process (done via Graph API), and for some reason this causes my custom web parts to fail to load for guest users.

The guest users have 'read only' permissions set within SharePoint itself, but this doesn't appear to rectify the problem.

Sites that do not have a site script load the web part fine.

3 years on, do we have a fix for this?