Teams won't allow me to attach a file to an assignment

Hi @H Vardy (KES Staff),

I hope everything is running smoothly on your end.

Just following up on the support thread we've been working through. I’d love to hear any updates you’ve received from your IT department. There are several others are experiencing the same issue, and Matt Grimley has shared some helpful recommendations that could assist your IT team in resolving it.

If you're still encountering the problem or need help with anything else, feel free to reply to this email, I’m happy to assist further.

We want to make sure everything is working as expected and that your experience remains uninterrupted.

Thank you for your patience and understanding throughout the troubleshooting process. 

I look forward to hearing from you soon.

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I have a solution from Microsoft Support, but it involves a Powershell Script that i can't see publicly listed (i.e. you might need to raise a ticket and ask for the script).

The issue was a bug in the Powershell Teams module prior to Version 7.3.1 (which was released in August). If your tenant admin manually created your Edu teams prior to the summer (or since, without updating the powershell Teams module), then you need to run the script.

The script Microsoft Support gave me (in ticket ID PII Removed) is called TeamSite-GenChanFolderTriggers-wPermAddV7.ps1 and should be run after running this commands:
Powershell pre-requisit commands
Install-Module Microsoft.Graph
Install-Module -Name MicrosoftTeams
Install-Module -Name Microsoft.Online.SharePoint.PowerShell
Install-Module -Name ExchangeOnlineManagement
Connect-MicrosoftTeams
Connect-ExchangeOnline
Connect-SPOService -Url https://<YOUR TENANT NAME>-admin.sharepoint.com
Connect-MgGraph -scopes "SharePointTenantSettings.ReadWrite.All","TeamSettings.Read.All","TeamMember.ReadWrite.All","Directory.ReadWrite.All","Group.ReadWrite.All","Sites.ReadWrite.All","Sites.FullControl.All"

~~I've asked my ticket handler if the script is publicly available and if so i will share the link here. Otherwise, get your admin to raise a support ticket and ask for the script.
~~
Update 25/09/25
Microsoft Support have published the full script here:
https://support.microsoft.com/en-us/topic/provisioning-classes-at-scale-using-powershell-and-microsoft-graph-3428f18f-ff38-4c46-a696-3318e463cbec#:~:text=Troubleshoot:%20granting%C2%A0permissions%20to%20existing%20class%20sites

We have the same issue, but if we make a new channel we are able to make and upload files to Assignments withing that channel

1. It is a PPT that I am trying to upload under 500MB. I have tried other file types and get the same message.
2. It is a school based account, I am a teacher and 'owner' of the group.
3. Windows 11
4. Both
5. All files
6. Not sure will check tomorrow.

Hi @H Vardy (KES Staff),

Thanks for reaching out to Q&A Forum. 

Based on the error message you received “There was a problem when attaching this file. Please remove and try again” and the context you provided, to help us investigate and resolve this issue, could you please confirm the following:

1. Does the issue occur for all file types? Try uploading a simple .docx or .pdf under 500MB.
2. Which account type are you using with your Teams? Is a personal account (@hotmail. @gmail. @outlook.com,...) or a work /school account provided by your organization?
3. Which system are you currently using (Windows, MacOS....)
4. Is the issue specific to OneDrive or also local files?
5. Does the issue occur for all file or just one?
6. Are other staff or students experiencing the same issue? If yes, you may need to check with your IT admin about a SharePoint or Teams policy issue. 

Once we have this information, we’ll be better positioned to guide you through the next steps. Please feel free to add any additional information you deem as necessary. Note: Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.  Thank you for your patience and your understanding. If you have any questions, please feel free to reach out. 

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