We have a project where we need to upgrade Web Forms For Marketers (WFFM) to make it work with Sitecore 7.2. The WFFM version that works with Sitecore 7.2 is the version 2.4 rev.140117. The WFFM version that we have in the server is version 2.3.0 rev 120216.
As per Sitecore website, we need to install three WFFM update packages as follows in sequence
Update WFFM module version 2.3.0 rev.120216 to version 2.3.0 rev.130118 (WFM2.3.0rev.130118.update)
Update WFFM module version 2.3.0 rev.130118 to version 2.3.0 rev.131126 (Web Forms for Marketers 2.3.0 rev. 131126.update)
Update WFFM module version 2.3.0 rev.131126 to version 2.4 rev.140117 (Web Forms for Marketers 2.4.0 rev. 140117.update)
I downloaded these three packages from the Sitecore website and started installing them. The installation of first two went smoothly. Before installing any package, I click on the ‘Analyze’ to see if there is any potential conflict. For the third package I saw the following conflict
Hmm, the original file has been modified? I haven’t done anything other than installing the two packages in sequence. I looked at the current version of Sitecore.Forms.Core.dll and that is below
The second package was supposed to upgrade the version of WFFM to 2.3.0 rev 131126, but wait, what is that Hotfix# 402448? I don’t know. Whatever, I don’t care because I don’t know what else to do other than installing the third update. So, I went ahead and installed the third package. As expected, an error occurred as mentioned in the analysis result and the Sitecore.Forms.Core.dll was not updated to 2.4.0 rev. 140117. The version is same as show in the above image.
At this point although I know things are not looking good, I decided check if the WFFM is working. I tried to open a form and got the following error.
This is a vague error because, my web.config has the right assembly redirection for the HtmlAgilityPack.dll.
At this point I decided to extract the Sitecore.Forms.Core.dll from the update package and copy that in the website/bin folder. Voila, the Forms started working.
I don’t know if this is a known issue. I haven’t found any reference of this problem in any forum or any place in the internet. I suspect that, the problem is with Hotfix version of the Sitecore.Forms.Core.dll, which was not updated in the Web Forms for Marketers 2.4.0 rev. 140117.update package.