All my debug builds will execute perfectly complying their own test but nott so my release builds!

All my debug builds will execute perfectly complying their own test but all my release builds don't comply this same severe test! I am a retired teacher of mathematics creating 4 programs containing the subjects I was teaching my 12-18 aged students. This test claimed the solution of all (nearly) 6.000 exercises  provided in over 140 files. Darran Rowe answered my question in the Microsoft's Visual Studio forum "Unable to compile a release version on Visual Studio 2017.". Darran stated that I used not properly initialized local variables. But I ordered Devpartner including BoundsChecker at Componentsource. What did I forget or neglect. What did I wrong.