If you are attempting to plot a function that returns complex values then that may explain why you are not seeing a plot. Plot only accepts real values.

You can try

Plot[{Re[expression], Im[expression]},{var,low,high}]

and that will show two curves, one of the real value and the other of the imaginary value. There is also ReImPlot[] which will do the same thing if you have a new enough version of Mathematica.

But none of this is dealing with your seeing Mathematica crash. I don't know how to diagnose that.

If your integration seems to be successfully completing and the problem seems to be that no plot appears then it is sometimes helpful to replace the

Plot[expression,{var,low,high}]

with

Table[expression,{var,low,high,(high-low)/10}]

and look at that result. If the result of that is anything other than a vector of real numbers then that perhaps explains why Plot does is not displaying a curve. Sometimes it takes more than ten points to show the problem. If you can't figure out how to fix it with that information then showing us what the table returned might let someone suggest what to try next.