Status: Investigating, partially resolved
Last updated: 19 October 2026
Tenants Impacted: Targeted Release
Summary
Lightning Tools is currently investigating several issues affecting functionality within SharePoint Online, which appear to be due to updates made by Microsoft on or around October 11, 2026.
We have received customer reports affecting Lightning Forms and have also reproduced other SharePoint Online behaviours internally that may affect Lightning Tools products. These issues do not necessarily have the same underlying cause, and symptoms may vary between Microsoft 365 tenants.
Our Support and Development teams are actively investigating the impact and monitoring related Microsoft/SharePoint reports.
Lightning Forms
We are investigating several symptoms affecting Lightning Forms, including:
- Customised forms intermittently failing to load and remaining on the loading screen.
- Lightning Forms functionality not appearing as expected within the SharePoint list interface.
- Problems opening the Lightning Forms customisation interface.
- Different behaviour between Microsoft 365 tenants.
Some of this behaviour has been reproduced internally.
Blank SPListForm issue
One issue affecting the form customisation interface appears relevant to a recently reported SharePoint Framework Form Customiser problem involving SPListForm.aspx. The public report describes affected SharePoint Online lists opening a blank SPListForm.aspx page before the SPFx Form Customiser is loaded.
Microsoft has published information relating to this issue within the Microsoft 365 Service Health dashboard under SP1503038. Microsoft 365 administrators can check Service Health in their own Microsoft 365 Admin Centre for the latest information available to their tenant.
View SharePoint/SPFx Form Customizer issue #11056
Update 14 Oct: Microsoft has acknowledged the issue and indicated that a fix should be available within 48 hours of the last update. Although the related article was briefly removed from the Admin Center, we have only recently been made aware of this acknowledgement.
Update 19 Oct: Microsoft resolved this issue on October 14, and they published a preliminary post-incident report on October 16, available in your M365 Admin Center within the above-named Alert.
Mismatched anonymous define module
We are also investigating reports containing the following browser console error:
- Mismatched anonymous define() module
This error appears to occur when attempting to perform various actions in Lightning Forms after the user has hovered over an element on the page that produces a Microsoft card (e.g. the Site name or a Person). This is due to a script conflict introduced in a recent Microsoft change, and may result in the customization dialog not being displayed, form customization edits not being saved, or forms being unable to open.
Update 14 Oct: We’re currently testing a potential fix that may resolve the reported issue.
Update 19 Oct: A fix for this issue was pushed out to Forms Studio clients on October 14; please accept the update in each of your Solutions. A similar update is currently being tested for CDN release in the standalone Lightning Forms SPFx app, and we expect to make this hotfix update by October 23. In the meantime, it may help to avoid hovering over card elements when working with Lightning Forms customizations.
Update 22 Oct: A fix for this issue is included in Lightning Forms version 3.12.0.0, released today. To get this fix, please download the new version (which also includes a number of feature updates), and upload it to your App Catalog. You may need to perform a hard refresh (Ctrl-F5) on your site to see the new version number in the license panel.
Forms Studio
We are also aware of an issue affecting Forms Studio where customers may be unable to open a solution and receive the following message:
There was a problem connecting to your SharePoint site
Our developers have advised that this behaviour is related to a recent Microsoft change affecting scripting capability and is currently investigating the issue.
At present, we do not have a confirmed workaround for this issue.
Update 14 Oct: We’ve implemented a fix for this issue, and it has already been automatically applied.
DeliverPoint
We have reproduced intermittent failures in SharePoint Online REST requests which can affect information retrieved by DeliverPoint.
In our testing, the same SharePoint REST request can return a 400 Bad Request and subsequently succeed when repeated without any changes. We have reproduced this behaviour independently of DeliverPoint, indicating that the observed request failure is not specific to DeliverPoint.
When these SharePoint requests fail, DeliverPoint may consequently report some SharePoint resources as inaccessible when running permissions reports.
A corresponding SharePoint REST issue has also been publicly reported. The report describes previously working REST requests involving $expand=RootWeb or $expand=ParentWeb returning a 400 response and System.ArgumentNullException.
View SharePoint REST issue #11055
A related SharePoint CSOM problem has also been reported publicly. This report describes failures when loading an SP.Web nested within another object's load and states that the changed behaviour was noticed on 12 October 2026 across multiple tenants.
View SharePoint CSOM issue #11057
There is currently no confirmed workaround that we recommend for the DeliverPoint behaviour.
Update 14 Oct: We’ve received acknowledgement from Microsoft through the GitHub channels raised above regarding the reported problems, and we will update this section as soon as further information becomes available.
Update 19 Oct: As of October 15, this issue appears to have been resolved by Microsoft.
Lightning Conductor
The intermittent SharePoint REST/CSOM behaviour may also affect Lightning Conductor when retrieving information from SharePoint.
Please see the above note regarding DeliverPoint for updates on this issue.
Social Squared
The intermittent SharePoint REST/CSOM behaviour may also affect Social Squared when retrieving information from SharePoint.
Please see the above note regarding DeliverPoint for updates on this issue.
SPFx components within Microsoft Teams
We are also investigating an issue affecting SharePoint Framework components when accessed through Microsoft Teams.
A public SharePoint Framework report describes SPFx components displaying a blank screen when loaded directly within Teams while the same component continues to load on a SharePoint page. The report states that the behaviour began on 12 October 2026 and may differ between tenants.
We have also reproduced related behaviour during our own testing.
View SPFx in Microsoft Teams issue #11059
Update 14 Oct: Microsoft has resolved this issue; however, it may take up to 12 hours for the changes to appear in your Teams environment.
What we know
At this stage:
- Several different SharePoint Online issues are being investigated.
- Some of the behaviour has been reproduced by Lightning Tools independently of individual customer configurations.
- Behaviour can differ between Microsoft 365 tenants.
- The publicly reported REST issue #11055 has been labelled as a confirmed bug by Microsoft on the SharePoint developer repository.
- Other related public reports remain under investigation and should not currently be assumed to have the same underlying cause.
We therefore do not currently recommend reinstalling or making substantial configuration changes to Lightning Tools products solely in response to these symptoms, unless advised to do so by Lightning Tools Support.
What Lightning Tools is doing
Our Support and Development teams are actively investigating the reported behaviour and reproducing issues where possible.
We are also working with our developers where appropriate and monitoring the related Microsoft/SharePoint reports.
As further information, fixes or confirmed workarounds become available, we will update this article.
Update 14 Oct: We’ve been able to implement some of our own fixes for issues introduced by the recent Microsoft update.
SharePoint REST $expand issue #11055 and SharePoint CSOM nested SP.Web issue #11057 have been acknowledged by Microsoft, but no official solution is available yet. Workarounds have been mentioned, and we’ll review internally whether they are applicable to our solutions.
SPFx Form Customizer / SPListForm.aspx issue #11056 Microsoft has been acknowledged and confirmed that a fix is being rolled out. It may take up to 48 hours for affected tenants to see the results.
What should customers do?
If you are experiencing unexpected behaviour that appears similar to the symptoms described above, please contact Lightning Tools Support.
Where possible, please let us know:
- Which Lightning Tools product and functionality is affected.
- Whether the behaviour is intermittent or occurs consistently.
- Whether multiple users, sites or lists are affected.
- When you first noticed the behaviour.
- Any browser console or network errors displayed when the problem occurs.
We will update this article as further information is confirmed.