Bruker has made several changes to their RTIfcClient.dll file over the years for integrated EDS WDS acquisition and quantification with Probe for EPMA.
The RTIfcClient dll that is distributed with 1.9.4.63 of the Bruker Esprit software is older than the RTIfcClient DLL version I have on my development computer, and which seems to work fine. The file time/date stamp on this dll is 11/27/2013.
I've attached it below. It should be copied to the Windows SysWOW64 folder for Win 7 64 bit or the System32 folder for 32 bit OSs.
Starting with v. 2.1 of Esprit, the RTIfcClient.dll file has been renamed to Bruker.API.Esprit.dll
PFE still looks for the original RTIfcClient.dll file name, so you will need to rename the new file.
After renaming, the file should be placed in the SysWOW64 folder so that all PFE/PI apps can access it.
It is perhaps sensible to remove all occurrences of the older version of RTIfcClient.dll before renaming the new version.
Gareth