When the dialog box appeared, I went to Legacy Patterns & More, then to Legacy Patterns, and I selected a pattern from the library.
The preview box in the dialog box shows the correct pattern.
When I click OK, the pattern is a grid not the actual pattern.
I tried other patterns from other libraries and the result is the same. For example, I went to the patterns within Trees. The preview shows the trees. After clicking OK, trees isn't being displayed instead it's a grid.