hold time violation in qsys system

Thank you all for your answers.

I check those paths in the technology map.

Those paths use different clocks, but they are related!

My main clock goes through an IOBUFF block, and then goes to CLKCTRL block. (Both blocks are automatically instantiated there by quartos and not by me, so I can't see them in the design files). the first node in the path use the main clock right after the IOBUFF block and the last node use the main clock after it pass the IOBUFF block(just like most of the design do).

Is it still o.k.? If not - what can I do to fix this hold time violation?

I will be also glad if you can aim me to some information about why quartos do it, what is it actually means and so on...