Upgrade 5.1RC to 5.1 vCard error: Error: Module Contact does not exist

[raj.alliacense]

Hi,

Recently patched our 5.1RC (test environment) to 5.1.

Now we get this error when clicking on the "vCard" button in the Contacts detail view.
Error: Module Contact does not exist.

when I click on vCards (which didn't work in 5.1RC, as I got this bug )

It seems simple, at some point "Contact' is being passed to the module validation which expects 'Contacts'. My efforts to debug this have run into the fact that 'Contact' is used extensively as an array key in internal varriables. Here is the main piece of the failing URL:

.../index.php?entryPoint=vCard&contact_id=100506cd-89f6-671e-ed1b-48bce0689719&module=Contact

If I change the &module=Contact
to
&module=Contacts

then it works fine.

Anyone know how I can resolve this?

[raj.alliacense]

To anyone else having a similar problem, here's what I found was the cause of the problem: a customized page was creating a bad vcard html form that submitted the wrong module name "Contact" in /custom/modules/Contacts/metadata/detailviewdefs.php

'preForm' => '<form name="vcard" action="index.php"><input type="hidden" name="entryPoint" value="vCard"><input type="hidden" name="contact_id" value="{$fields.id.value}"><input type="hidden" name="module" value="Contact"></form>',

Changing this from Contact to Contacts fixed the problem. Still not sure how the error cropped up.