It looks like the RTShipping class has been customized to add Cerasis real time shipping. The error message you are getting is a direct result of that integration; no shipping methods are being returned and AspDotNetStorefront has no shipping method to fall back on so the error message is being displayed. You'll have to check (or have the developer that did this for you check) that the parameters being sent to Cerasis are correct in order to retrieve rates from them. I'd also rethink the error message in your custom uhoh.aspx page (if possible...I can't tell if that is your page or their page from what you've provided here)...
<span id="Label1" class="RedAlert">There was error, we are not that good at coding!</span>
as a customer if I saw that particular error message I'd consider not returning.
<a href="http://www.aspdotnetstorefront.com">Shopping Cart Software</a>