I can't say i've seen that error before, but it looks like it's having problems adding the web part to the page. Is the FBA Pack deployed and feature activated on Sharepoint:88? Do the web parts work if you add them to a standard SharePoint page on that site?
I knew I forgot something. FBA is deployed sharepoint:88 and the webparts work
What do you mean by: "feature activated on Sharepoint:88"?
I mean, make sure that 'Forms Based Authentication Management' is activated under the Site Collection Features on SharePoint:88.
SharePoint:88 -> Site Settings -> Site Collection Features
Yes it's activate
I'm not sure. I'd say try to pinpoint the problem by removing everything until you have a working page, and then incrementally add items back until there's an issue. You may want to try using the simple.master master page as well - that's what the login pages use. Maybe take a look at the built in login pages and look for differences.