Warning in par simulation

[lmtg]

at 454.670 ns(3): Warning: /X_FF HOLD Low VIOLATION ON I WITH RESPECT TO CLK;
Expected := 0.142 ns; Observed := 0.133 ns; At : 454.67 ns

Any idea how to solve this warning I get in the post par simulation?? I get when I input a zero to the block..

Thank you in advance.