InfoPath Dev

I got the following error on the all infopath forms on over live intranet environment.and its comes sometime and sometimes its works..

I got the two message on infopath forms either

"There has been an error while loading the form. A required resource could not be downloaded. To try to resume the download, refresh the page."

                                     0R

 critical error saying that The security validation for this form is invalid.

 thios error are on fornt end on infopath forms....

event viewer error likes..

The form template failed to load. (Username, Form Name:  form, IP: , Request: formpath, Form ID: urn:schemas-microsoft-com:office:infopath:-form:-myXSD-2009-11-30T11-52-29, Type: InfoPathVersionUpgradeException, Exception Message: Exception of type 'Microsoft.Office.InfoPath.Server.Util.InfoPathVersionUpgradeException' was thrown.

 I have cleared the cache for config and tried to reconfigure the infopath forms through stsadm cmd but did not help anything...

we have updated the cumulative june update for moss 2007..then after this above errors strats sunndenly....

help me if you have any solutions? 

It sounds like what is happening is that you updated the form template (XSN) and the old XML doesn't match the schema of the new one. If you can create a new form using the browser, that's another clue that the schema is incompatible. You should consider using separate content types for versions of the form that don't have the same schema. Of course, best practice is never to move, delete or rename data source fields (schema nodes). When you add new fields, nake sure they are not required. Then, the upgrade should work on XML files saved with a previous version without any problem.

Hi Patrik,

Thanks for your reply...

as i said I have done recenet update (june cimulative update for moss)then all forms strats giving error.....for this i am assuming i am not sure because the all forms are running fine and one week after update  above error starts.....I have removed the custom security validation from central admin but its also did not help me...

 as you said  "You should consider using separate content types for versions of the form that don't have the same schema"

 what do you mean by that I just want to understand how can i resolve for all forms (40 forms on live)?

after publishing the existing form and deplyoed on central admin its working now for some time...and start giving the error again.. do you have other alternative solution?