Microsoft List won't let me edit cards anymore

Question

Microsoft List won't let me edit cards anymore

Tristian 0

I wanted to add a priority tag to the tasks in MS List connected to our teams channel but now it just crashes or goes blank.
I added this code in the custom section because the column I wanted to show wasn't an option in the drop down. See code and screenshot below.

After clicking on customize card or format current view > edit card you can see the panel to the left goes blank.

User's image

inserted json:

{

"$schema": "https://developer.microsoft.com/json-schemas/sp/v2/board-formatting.schema.json",

"hideSelection": false,

"formatter": {

"elmType": "div",

"attributes": {

  "class": "sp-card-container sp-card-container-noPadding"

},

"children": [

  {

    "elmType": "div",

    "attributes": {

      "class": "ms-bgColor-white sp-css-borderColor-neutralLight sp-card-borderHighlight sp-card-subContainer sp-card-subContainer-borderRadius"

    },

    "children": [

      {

        "elmType": "div",

        "attributes": {

          "class": "sp-card-displayColumnContainer"

        },

        "children": [

          {

            "elmType": "p",

            "attributes": {

              "title": "[$Title]",

              "class": "ms-fontColor-neutralPrimary sp-card-content sp-card-highlightedContent",

              "role": "heading",

              "aria-level": "3"

            },

            "txtContent": "=if ([$Title] == '', '–', [$Title])"

          },

          {

            "elmType": "div",

            "style": {

              "display": "=if([$Priority] == '', 'none', 'inline-block')",

              "padding": "4px 10px",

              "border-radius": "12px",

              "font-weight": "600",

              "font-size": "12px",

              "margin-top": "8px",

              "width": "fit-content",

              "background-color": "=if([$Priority] == 'High', '#FDE7E9', if([$Priority] == 'Medium', '#FFF4CE', if([$Priority] == 'Low', '#DFF6DD', '#F3F2F1')))",

              "color": "=if([$Priority] == 'High', '#A80000', if([$Priority] == 'Medium', '#813E00', if([$Priority] == 'Low', '#107C41', '#323130')))"

            },

            "txtContent": "[$Priority]"

          }

        ]

      }

    ]

  }

]

}

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1 answer

Your answer

Answer 1

Vivian-HT 17,610 Microsoft External Staff Moderator

Dear @Tristian

I understand how frustrating it can be when the card editor suddenly stops working, especially after trying to customize it.

In this case, I recommend you try clearing the Microsoft Teams cache to rule out any client-side rendering issues, especially since the list is being accessed through Teams. For reference, please refer to this article: Clear the Teams client cache

Moreover, you may also try repairing the Microsoft Teams app to rule out any client-side issues. Go to Windows Settings > Apps > Installed Apps > Advanced options > Repair and then Reset

However, if the issue still persists, this behavior might be caused by custom JSON formatting applied to the card. Therefore, I recommend resetting or removing the custom formatting to check whether it can load normally again.

If possible, please try to open the list directly in Microsoft Lists for web or SharePoint > go to “Format current view,” switch to advanced mode, and remove the JSON entirely, then save. For more information, please refer to What is a list in Microsoft 365? and Microsoft Lists

Another option is to create a new view for the list and set it as the default. Views control how items are displayed (including card formatting), so try creating a fresh view to bypasses the broken configuration and allows you to continue working

Moreover, if the issue still persists, to better isolate the cause, could you please help confirm a few things:

Are you using Teams app on desktop or Teams for web?
Does the issue occur only in Microsoft Teams, or do you see the same behavior when opening the list directly in Microsoft Lists for web or SharePoint (browser)?
Did the problem start immediately after adding the custom JSON, or was it working for some time before breaking?
Are other users in your team experiencing the same blank panel when editing the card, or is it only happening on your side?‌
Have you tried accessing the list from a different browser or device, and does the behavior remain the same?

Note: Please understand that as a forum moderator, my role is to provide general guidance and troubleshooting support. I don’t have access to internal systems or backend tools, and I appreciate your understanding of these limits.

Please try the steps above and let me know if they work. If not, we can continue working together to narrow this down.

The first response may not always resolve the issue right away, but with your help and more details, we can work toward a solution.

Thank you for your patience and understanding. I'm looking forward to your reply.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

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.

Vivian-HT 17,610 Reputation points Microsoft External Staff Moderator

2026-06-29T06:00:16.3633333+00:00

Dear @Tristian

Good day and I hope you're doing well. I just wanted to check in and see if there is any update from you.

Looking forward to your update.
Tristian 0 Reputation points

2026-06-29T16:56:55.02+00:00

Hi @Vivian-HT , thank you for your advice! I didn't want to delete all the data in the app because I have a lot of channels and things set up (i.e. Atlassian connected), but I did try to repair it, to no avail. This is the screenshot after the repair attempt:

I then tried deleting the JSON from sharepoint, but the first click on customize card didn't do anything and the second click rendered the whole page blank. Should I just delete the whole list and remake it? Also, how do I include a tag that is not the bucket itself. For instance, the buckets are To Do, In Progress, and Completed but I want to display tags from a different column (choice: Priority - High, Medium, Low) but there it doesn't show up under card designer.
Vivian-HT 17,610 Reputation points Microsoft External Staff Moderator

2026-06-30T03:34:19.26+00:00

Dear @Tristian

Thank you for the update, and I completely understand your concern. ‌

Based on what you described, in this case, if possible, I recommend you try creating a new view from the view dropdown in SharePoint in your browser. Keep it simple (a standard list or gallery view), include your columns such as Priority, and set this new view as the default.

If the issue still persists, I recommend you create a support ticket with Microsoft in the M365 Admin Center. At this point, the view configuration may need backend correction, which isn’t something we can access from the forum. ‌The support team can investigate at the backend level and help recover or reset the affected list view safely. ‌Additionally, they can check whether there are any supported options to help you display tags instead of buckets. For reference, please refer to Get support for Microsoft 365 for business

Note: If you are user, please reach out to your IT Admin to help you create a support ticket to Microsoft Support for further help. For reference, please refer to How do I find my Microsoft 365 admin?

Please understand that as a forum moderator, my role is to provide general guidance and troubleshooting support. I don’t have access to internal systems or backend tools, and I appreciate your understanding of these limits.

Thank you for your patience and understanding. I'm looking forward to your update.
Tristian 0 Reputation points

2026-07-01T16:30:20.82+00:00

Hi @Vivian-HT ,

Thanks for your suggestions. I think creating a new board will circumvent the issues I'm seeing with my current one. I did try setting up a new list and gallery to test things out. The list view works well, but I was hoping to keep something closer to the bucket-style view, with action items group by status and each item bearing a priority tag.

With the gallery view, I ran into a similar limitation as the bucket view--the only tag options I could display were the same as the bucket categories, which felt a bit redundant. But the title and status were all the card designer currently allows me to select (see below).

Is there a way to expand the information shown on each card in the card designer?
Vivian-HT 17,610 Reputation points Microsoft External Staff Moderator

2026-07-02T04:09:29.8533333+00:00

Dear @Tristian

Thank you for the additional testing and feedback. It's encouraging that creating a new board helped work around the original issue.‌

Since you want display additional metadata such as Priority (High / Medium / Low) on each card, I recommend you consider using custom JSON card formatting rather than the standard Card Designer experience.‌

Because this falls into the more advanced area of Microsoft Lists JSON formatting, to make sure you receive the most accurate and helpful guidance, I'd also recommend posting your requirement in the Stack Overflow community, will connect you with the SharePoint and Microsoft Lists developers/experts and other partners who regularly share their knowledge, custom formatting examples/JSON solutions and learn from similar interactions.

Here's the official site: https://stackoverflow.com/questions/tagged/json

Please note that Stack Overflow has guidelines such as requiring a descriptive title, a complete and concise problem statement, and sufficient details to reproduce your issue. Feature requests or overly broad questions are considered off topic.

Disclaimer: Microsoft provides no assurances and/or warranties, implied or otherwise, and is not responsible for the information you receive from the third-party linked sites or any support related to technology.

Since you've already encountered issues with the card customization experience and the available fields don't meet your requirements, I would also encourage you to submit a support request through the Microsoft 365 Admin Center. This allows Microsoft Support to confirm whether the behavior is a product limitation, a known issue with the current Card Designer experience, or something specific to your tenant. For reference: Get support for Microsoft 365 for business

I hope you can understand this recommendation. Thank you for your patience and understanding.