Since GROMACS was parameterized for simulations in the condensed phase, I guess this kind of errors can occur. Nevertheless, it seems that your system does not converge to the energy limit, possibly for a poor initial configuration geometry or lack of memory in your workstation. Try to check these posibilities.
Only you know your system and the initial parameters for it. Check the literature (experimental data or quantum chemical calculations) to get insight about angles, dihedral and bond distances in your system and try to reproduce an initial configuration with the optimal parameters that you checked. Right now I do not know if you have a protein, a polymer system, a single ligand...