The key words are "assertion failed" - which is a very specific indication of what the problem is.
Somewhere in your code, you have a line like this:
ASSERT(k == STD_VECTOR_MAT)
Which has performed the test and decided that it can;t proceed as a result becuase for some reason
k
is equal to
STD_VECTOR_MAT
Why this is a problem, we don't know: but the rest of the message tells you where in your code it is: function
getMatRef
in your
matrix.cpp
file.
So look at the code, find the ASSERT, and work out why it's a problem!
We can't do that for you: we don't have your code, and couldn't run it if we did!