Multilinetextbox Validation not working

[ektoplasma25]

Hi all, I have a Problem with the validation rule on my Multi-line textbox. In the picture below you can see two multi line textboxes the first one is a list column, the second one is a multi line textbox out of the General section. Both of them has added a rule with the same condition. 

Rule on mtxt List ColumnRule on mtxt Gernal section

Why does the rule not work on the multilinetextbox from the list column?

[ektoplasma25 · Accepted solution]

Changed the Type of text to allow to "Plain Text" or "Rich Text" will solved the Problem.