When working with InfoPath, a weird behavior can occur with SharePoint site columns where the columns may seem to disappear when editing their type.
Recreating the Problem:
Let’s say we create a simple form that will capture users’ comments with their first and last names as show here:
The first and last name fields are single line textfields while the comment field is a multiline textfield.
The next step would be to publish the form and create a content type with SharePoint columns mapping to these fields to enable the form to be reused across several libraries. In order to accomplish this, you can either create those columns manually and map them to your fields or let SharePoint create those columns automatically using your fields’ names and information. The weird behavior happens when SharePoint automatically creates the columns for you. Once this is complete, the SharePoint InfoPath columns will show up in the site column gallery under the Microsoft InfoPath group as show here:
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We have originally set the "Comment" field in the InfoPath form to be a multiline so that it can receive more text and the data won’t be cut-off by the 255 character limit, however we see it is set to a single line type SharePoint column. Any entries to this comment field will only retain up to 255 characters. To correct this, you will need to change the type of the SharePoint column where the Comment field maps to simply by changing the type from Single line of text to Multiple lines of text.
After updating the column’s type, you will notice that the column has disapeared from the Site Column Gallery:
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While the column seems to be gone, it is in fact just not referenced. The form will continue to retain information in this field.
Avoiding Data Misplacement:
While your form is receiving information, changes to this field will not be possible. One thing to prevent losing access to the column setting is to make a shortcut of the column from the Site Column Library before modification (from single line to multiline) as shown here:
Should you be unable to do this small trick because you created a form and modified the now lost column, the only option now is to start over with a new form and republish that form with a new name so that new SharePoint columns can be created.
