Hello all:

Had an issue that I've resolved and wanted to share with you.

We rolled out an InfoPath form across the company and had a few users
unable to save changes, with InfoPath reporting this error (including
data from the "more details" button):

InfoPath cannot save the form.
The OnSaveRequest function returned a value indicating that the save
failed.
Details for the error are:
The following error occurred:
Error in loading DLL
File:script.js
Line:234

The line in question was simply the first encountered reference to
XDocument in the script we run to validate the form before saving. The
exact line was:
    for (var i=0; i<XDocument.Errors.Count; i++)

In the end the problem was that MSADO15.DLL was no longer registered.
Running
    regsvr32.exe "c:\program files\common
files\system\ado\msado15.dll"
at the command prompt resolved the issue.

Hope this is helpful to anyone else running across a similar error.

Niels