Using the Umbraco Forms 4.3.2, I'm experiencing an unusual error on new forms I create.

Can anyone give me any insight into the following exception? It happens when submitting a form (front end) with a mere 4 fields and 2 workflows (send email).

Below is just a shallow stack trace:

System.NullReferenceException: Object reference not set to an instance of an object.
   at Umbraco.Core.Cache.HttpRuntimeCacheProvider.GetCacheItem(String cacheKey, Func`1 getCacheItem, Nullable`1 timeout, Boolean isSliding, CacheItemPriority priority, CacheItemRemovedCallback removedCallback, CacheDependency dependency)
   at Umbraco.Core.Cache.HttpRuntimeCacheProvider.GetCacheItem(String cacheKey, Func`1 getCacheItem, Nullable`1 timeout, Boolean isSliding, CacheItemPriority priority, CacheItemRemovedCallback removedCallback, String[] dependentFiles)