While publishing an InfoPath form, you wil get an error "The server is running InfoPath Forms Services, but the compatibility settings for this form template is InfoPath only".
This issue is due to the reason that InfoPath form was not configured that it can be opened on browsers also. You need to go to the form template and modify the settings to open the infopath form in a browser or InfoPath applicatoin. If you do not configure the below settings in the fix, forms will be always opened in the InfoPath application on the client. If the user do not have InfoPath installed on his machine, he will get the error. If you have a requirement that the form needs to be open in the InfoPath only, then just ignore this fix.
Go to the form template(.XSN) and do the following:
1. Tools -> Form Options
2. Select "Compatibility" from the categories on the left hand quick launch
3. Check the option "Design a form template that can be opened in a browser or InfoPath".
4. click OK