Legal Question in Construction Law in California

You're asking a fairly general question of law because other terms and conditions of the particular contract may interpret such a clause in various ways. Simply becuase someone else prepared the contract does not negate your responsibility to investigate site conditions and ensure you can perform the work called for in the contract. As a contractor, it's generally your responsibility to review the plans/specs and consider whether you can perform the work given the site conditions. Case law generally holds the contractor responsible for field changes and other issues when the contractor could not perform the work as planned because of site conditions where the contractor would have been able to advise the owner of necessary changes had a proper inspection been performed beforehand.

The clause you quote does not make you responsible for errors or omissions in the plans and specifications. What it makes you responsible for is being aware of the existing site conditions before bidding, and if there are conflicts between the plans/specs and the site conditions, that could be seen by proper review of the plans/specs and inspection of the site conditions, that clause will preclude you from making a change order claim for a differing site condition.