I have a form library in SharePoint 2010 (on premises) with a form template and everything configured to render the form in the web browser. Everything has worked well to date. I need to update the form to change some text. When I publish the form I get the message "The form template has been published to the server but it can only be opened in the InfoPath Filler because it contains features that are not compatible with Web browsers. To fix this problem, close this dialog and review the errors in the Design Checker task pane." and the form does not render in the browser.
I have double checked everything, Design Checker shows no issues and the form type is "Web Browser Form (InfoPath 2010)", and old versions of the form continue to render in the browser. Because this is a quasi legal document I have to publish different versions of the form to the library, adding a version number to the file name. See http://social.technet.microsoft.com/wiki/contents/articles/18109.sharepoint-2010-how-to-maintain-infopath-form-changes.aspx. I've updated the form in the past with no issues.
I do not recall if the form was originally created and updated using InfoPath 2010. I am currently using InfoPath 2013. The SharePoint 2010 farm does not have many updates because the organization is moving to SharePoint Online and does not want to take the risk of applying SharePoint updates given their reputation.