The first thing you need to do after installing the add-on is to prepare your scene:

-Subdivide any object that will be curved or bent or twisted.

-join the parts that will be animated together as a single object.

-separate the objects that would be animated individually.

-For floor tiles, separate them, and then put them in a collection together and make sure each of the tiles has an individual origin

-Then select your object and choose a preset and your animation is ready.

It's not uncommon for Blender to crash when undoing operations involving complex changes or interactions with external files. In your case, the operator is applying a curve modifier and performing various transformations on the selected object, which can be a complex set of changes.

Right now the solution would be to just click once anywhere after selecting the curve animation then it won't crash if you undo.