Sorry, I need to clarify the document cache location for FileUltimate.
If you do not set TemporaryPath configuration property, then by default this path will be used:
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\YOURSITE\XXXXXXXX\FileUltimate\DocumentCache
or for 32-bit process (ie. if “Enable 32-bit apps“ is enabled in IIS app pool settings):
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\YOURSITE\XXXXXXXX\FileUltimate\DocumentCache
So you should clear one of the above folders to clear document cache after you change "Load User Profile" setting in IIS.
For locating the cache folder easily in future, you may want to change the location to somewhere you know.
For example, you can change it by putting the below line into the Application_Start method of your Global.asax.cs:
FileUltimateConfiguration.Current.TemporaryPath = "~/App_Data/Temporary";
Alternatively you can specify the same setting in <appSettings> tag of your Web.config:
<add key="FileUltimate:TemporaryPath" value="~/App_Data/Temporary" />