Logic matrix. Find logical error at the matrix. In computer programming, a logic error is a bug in a program that causes it to operate incorrectly, but not to fail. Because a logic error will not cause. Because a logic error will not cause the program to stop working, it can produce incorrect data that may not be immediately recognizable. You can set an assertion on a condition that must be true according to the logic of your program. The assertion has no effect unless a logic error occurs. Could someone please help me with this logic error?