In both 2.88 and 2.90, if you set up a product, in the following area:

User Roles Setup - Roles to add after successful payment

and you checkmark one of the roles, but do NOT provide a Role Expiration value, you will get an error after the final Submit Order button in the ordering process:

The cure is to supply a number, or don't checkmark a role.

I tested this with both manual gateway and authorize.net and didnt see the error. Can you post a screen shot of your cart settings product setup so I can replicate your exact setup. You might also want to try downloading and installing the latest version 2.9 from the downloads page and install it on a new dnn install to see if the issue is related to your upgrade.

-Scott

How do I get updates? I see on the forum there is a version 2.93 and I think I should get updates for a few months.

This is now fixed and you can check all the roles you want and add the expiration days to any of the roles. This fix is availible in cart v3.05. This was a tough bug to figure out. It turned out the error started happening with in dnn 5.2 and above something was changed in dnn with encrypted cookies or forms authentication. For any other dnn module programmers out there here is what fixed it.

We changed the following code:

FormsAuthenticationTicket ticket = new FormsAuthenticationTicket(1, Context.User.Identity.Name, DateTime.Now, DateTime.Now.AddHours(1), false, strRoleNames);

// Encrypt the ticket
string cookieStr = FormsAuthentication.Encrypt(ticket);

// Send the cookie to the client
Response.Cookies["portalroles"].Value = cookieStr;
Response.Cookies["portalroles"].Path = "/";

To this:

//Clear the user's cached/stored role membership, will reload on next page cycle
PortalSecurity.ClearRoles();
DataCache.ClearUserCache(PortalId, UserInfo.Username);