On what basis ... the simplest hypothesis is the most likely one to be true?" Occam didn't say that. The true hypothesis is the one confirmed by experiments.

On what basis ... the simplest hypothesis is the most likely one to be true?" Occam didn't say that. The true hypothesis is the one confirmed by experiments. One would use Occam's razor to choose among equally valid explanations. Now, when you don't have a valid explanation, don't expect William of Occam to fix that for you.