In Sitecore.NET 8.1 (rev. 160519) + Web Forms for Marketers 8.1.rev. 160523,
We are getting problem into executeing WFFM Custom Save Action in CD environment with Submitting form with image. If we do not upload any image and submit the forms, WFFM Custom Save Action work fine. In CM sever form is submitting perfectly with/without image.
TO Fix the Issues i trying following thing :- I followed this article but in CD server when I add "remoteWfmService" in connectionStrings.config I gets error "The entry 'remoteWfmService' has already been added". Also instead forms.config we have sitecoreforms.config there already we have this setting
Sitecore Web forms for marketers 2.4 file upload on content delivery server error (WFFM)
I tried this article as well by enabling the Clint Action checkbox true but no luck . http://sitecorecode.com/index.php/2016/05/23/wffm-custom-save-action-not-woking-on-cd-environment/
In Log file I got this entry against my Save Action Item ID
WARN [WFFM] Could not find configuration node: databases/database[@id='master']
WFFM form submit action will upload the file on Master database Media library. As you are on CD server, so WFFM form will not get Master database and hence you are getting error "Could not find configuration node: databases/database[@id='master']".
For this you should configure WFFM CD modules which comes in ZIP file with name "Web Forms for Marketers CD 8.0 rev.zip". So you have to unzip this and manually paste the WFFM config and DLL files on your CD server.
Also check the presence of SwitchMasterToWeb.config file in App_Config\Include folder on your CD server. It must be there. I hope this will work for you.