In vco phase noise simulation with spectre I always get this warning:

The Floquet eigenspace computed by Virtuoso(R) Spectre(R) PSS analysis appears  to be ill-defined. PNOISE computations may be inaccurate. Consider re-running the simulation with smaller reltol and `method=gear2only'.

I did everything as suggested, but could not solve this problem.

Does anyone have the same experience and solution to that? Thanks!