Hi Sally, 👋
It looks like the issue might be related to how the display attribute or caption expression is configured in your Combo Box settings. Here are a few things you can check:
Display Attribute:
Go to your Combo Box properties → General tab → Caption (or Display attribute).
Make sure it points to a string attribute (like Name or LabelText) of the entity used as your data source.
Verify the Data Source:
Ensure that the Combo Box data source is returning the correct list of items — whether it’s from a microflow, XPath, or association.
If Using a Custom Expression:
In Appearance → Caption template, use
{AttributeName}
or a string expression like
$currentObject/Name
Make sure the expression evaluates to text.
For Multi-select Combo Box:
The display field may not automatically concatenate selected items.
In that case, you can bind the selected items to a non-persistent helper entity and use a text template or custom expression to display them properly.
Recheck Read/Write Access:
If the attribute used in the Combo Box doesn’t have write access, Mendix won’t show or update the selected value in the input box.
Optional Fix (UI Update):
Try clearing the browser cache or updating to the latest version of the Combo Box widget from the Mendix Marketplace.
Hopefully, this helps resolve the issue!