What you are asking has nothing to do with UniGUI. In such way works any native application. After AV crash ususally any native application will work unstable or does not work at all. Only app with managed memory like .net or java has more protection from such errors.
You must fix AV in any native application, VCL, UniGUI, C++, there is not the difference. Licensed or trial, Delphi, C++, or any other one native language.