Check out this post w/some simulation options, which mentions PAC Project Demo, which includes PAC Sim. If you don't already have SoftPAC (or PAC Project Professional, which includes it), PAC Sim may be all you need, especially if this is just a temporary situation until you get your real hardware. PAC Sim will run for 12 hours at a go and has MOST of the features that SoftPAC includes.
BTW, what error(s) are you seeing, exactly? You can disable your whole I/O Unit so that the PAC doesn't try to communicate with it at all. Then you'll just be using IVALs (vs. the "real" XVALs) for your logic/HMI. No timing out waiting for a connection that's not going to happen.
Here's the check box to look for and un-check in PAC Control config (just double-click on the I/O Unit in your strategy tree to see this):
Hope that helps!