S4S Form Mapping Wizard Error

If you have confirmed that your connection to Salesforce is working correctly and you load the S4S Form Mapping wizard to see the following error message: Exception occured when loading Sitecore Forms. Check logs for more information.

If the log file does not have a related error message, then it is likely that the API Controller Type has not been cached.

To resolve this, we have found that deleting the MS-ApiControllerTypeCache.xml file will regenerated the cache. The MS-ApiControllerTypeCache.xml file can be found in the C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\root\xxxxxxxx\xxxxxxxx\UserCache directory. You may also need to reset the App Pool for the website.