Many synthesis tools don't support integer division/modulus/remainder unless the calculation is trivial, such as division by a power of two. If your value isn't a power of two, then you are probably out of luck.
Maybe you can use another approach such as building your own math module, or using a math core from your software's IP library.
Or maybe you can approximate the division by multiplying by the fraction 1/K instead of dividing by K.
If both operands are small, you could fetch the result from a ROM lookup table.