Squash infertility

by Glecar
(Pitt Meadows, BC, Canada)

We planted pumpkin, hubbard, spagetti, zukinni and acorn squash this Spring and there was no viable harvest. The plants continued flowering until September, but no fruit. The Zukinni produced some potential fruit, yet they quickly wilted and rotted like they were infertile.
We would like to know what went wrong so we can learn for next year. If this is a fertilization problem would cultivating mason bees be a solution?