During animation playback, data-blocks are reallocated, so storing pointers to the resulting data is not okay. Instead, the data should be retrieved from the context. This works when the applied search item is the "dummy" item added for non-matches. However, it still crashes for every other item, because the memory is owned by the modifier value log, which has been freed by the time the exec function runs. The next part of the solution is to allow uiSearchItems to own memory for the search items.