This error has been killing me of late. I have a SharePoint 2010 list with a form that’s customized in InfoPath. Admittedly, the list is *very* large… as in over 74000 items. I know… it should be smaller, but that’s another discussion for another time.
The form has always taken a bit of time to publish, and the time has increased as the list has grown. Recently, I made a small change to the form, and it would no longer publish. I started getting the following error – “The SOAP message cannot be parsed”:
I tried a number of methods to “fix” the problem, based on various online posts and blog entries. Most of them recommended changing IIS timeout setting, but that wasn’t solving it this time for us.
Then I found this blog entry: https://spjohnadams.wordpress.com/2012/11/11/soap-message-could-not-be-parsed/
It was this part that was the revelation:
I had one calculated field in the list, and ironically it was one I really wasn’t using. I deleted that field and then republished the form. Not only did it publish, but it did so in about 10 seconds (as opposed to the minutes it used to take).
I would have never thought that a calculated field would have that effect on publishing a form, but there you go.
SharePoint Duffbert 
Thank you for this! I was having the exact same issue and deleting the calculated field worked like a charm.
Again, thank you. I had one calculated field in the list, and ironically it was one I really wasn’t using. I also deleted that field and then republished the form. Not only did it publish, but it did so in about 10 seconds (as opposed to the minutes it used to take).
I would have never thought that a calculated field would have that effect on publishing a form, but there you go.
I have the same issue, but I need the calculated field.
what if I don’t want to delete the calculated fields? I need these fields in the list.
excellent. Thanks for the post!!!!