I tried to restart a QST calculation in DMol3 (v4.2), and after computing the energies and gradients of the reactant, product, and the intermediate, the output is:

Message: Commencing conjugate gradient refinement
Forward Step : 1.0100
Integration points, checksum 0 101774 814041 0.000000
Error on Cholesky decomposition of overlap matrix 1

What could have caused this error, and how can I avoid it?

Thank you-
Vladimir Shapovalov