Forum Discussion
Unable to change existing column type from Text to Multiline Text
I have never seen this before. when I change the field type to multiline text I get: Non-supported field type change. This is when using Classic. In modern I get the same thing. In PowerShell ...
As it's a very old thread still replying, may help someone.
I was also facing the same issue.
Noticed that the column type was single line text used in a calculated column.
As a calculated column can't be based on multi line text, list is not allowing to change this single line text column to multi line text column.
Hope this may help