custom form for list not allowing submission

Hi @Lola Rubun 

Welcome to the Microsoft Q&A forum. 

Thank you for reaching out and I appreciate you sharing the screenshot. I’m sorry you’re running into trouble with your custom form not submitting.  

The error you’re seeing usually happens when something inside the list or the custom form has changed in a way that prevents the form from saving new entries. Even a small change in the list can cause the custom form to stop submitting, which is why this issue can show up suddenly even if the form was working fine before. 

The form usually stops submitting when something in the list no longer matches what the form expects. This can happen if a field becomes required or set to unique, if a column was renamed or deleted, or if the custom Power Apps form needs to be republished after list changes. It can also be caused by lookup, choice, or people fields not getting valid data due to permission or source updates. In some cases, the browser may simply be loading an outdated version of the form. 

Here are some steps you can try to check: 

1/ Try different paths to create the item 

• Open the list > New (standard form) 
• List settings > Form settings > Use the default SharePoint form > Save > test a submission. 
• If default form works, the issue is in the custom form app (skip to section 3). 

2/ Use Quick Edit (Grid view) 

• Try adding a row in Grid view (inline). 
• If Grid works, the error is form‑specific (validation/Power Apps logic). 

3/ Browser isolate 

• Use InPrivate/Incognito, another browser. 
• Clear cookies/cache for Outlook, disable browser extensions (ad/script blockers or VPNs), or try another browser (Edge, Chrome, Firefox).  
  • Go to https://outlook.office.com.  
  • If it works there, clear cookies/cache for Outlook, disable browser extensions (ad/script blockers or VPNs), or try another browser (Edge, Chrome, Firefox).  
• Sign out/in once, just in case stale tokens are involved. 

4/ If you're using a customized Power Apps form 

Please try opening the form in Power Apps and republishing it: 

• Go to List > Integrate > Power Apps > Customize forms

• In Power Apps, select Publish (Ctrl+Shift+P) > Publish to SharePoint

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.  

Additionally, as other users have raised similar concerns and may not be aware of where to share their feedback, I hope this response helps clarify the situation and suggests a potential next step. Highlighting this information can make it more visible to others in the community who may be facing the same issue, making it easier for them to find guidance and contribute their feedback as well. 

Thank you again for your time and for raising this important usability concern. If you have any further questions or need additional assistance, please don’t hesitate to reach out. 

I look forward to your thoughts on this. 

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