Problems using inverse Laplace function ilaplace - result not-understandable

Hello,

I got a Laplace Transformation which only contains a few numbers and the standard variable s and it sorta looks like this:

-43980465111040000000*(3026775+989755*s+80361*s^2)*exp(-s)*(-1+exp(-1/2*s))/(133118972286468096000000000+61984088406569779200000000*s+10847979631731015680000000*s^2+1118183534238892032000000*s^3+74563161135303884800000*s^4+3333741245649387520000*s^5+96018591235073638400*s^6+1511540416145522688*s^7+5332323531457823*s^8+2199023255552*s^9)/s

So s is contained in various forms. Now, when I try to invert this back into the time domain with the ilaplace function I get odd results containing _heaviside, _alpha, _Z, _alpha = RootOff besides the regular variable t. I cannot use the result nor do I know what it means. I need a simple function/ equation in the end only containing t. What am I doing wrong?