C# Reflection not Working for mid size (300KB) executabeles

i am loading exe using reflection in C# but it doesnt work for all the Executables:

not sure but the following info might be useful

Executables with size around 5 to 10 KB works fine but sizes around 300KB doesnt seem to work.

Side Notes: i get the desired output for small sized exes, but for large size exes there is no clue why nothing happens , there is no errors , no exceptions , nothing (i read somewhere that reflection is slow so i tried waiting for few hours still no luck)

all the suggestions are appreciated