Laserfiche 9.x upgrade permanently breaks older Kofax Capture functionality on the same box.
Just a warning that if you have an older LF client on a PC that is also on an older Kofax Capture client, when you upgrade the LF client to 9.x, it will permanently break the Kofax functionality (except the VRS drivers, which will still work).
There is a shared DLL that both Kofax and LF use, to handle network calls on behalf of a non-shared Kofax DLL (PFcaptur.dll), and the shared DLL gets removed or changed in the new LF 9.x uninstall/upgrade process (without warning). The error references the Kofax non-shared DLL (not the shared DLL that Laserfiche overwrites, and both Kofax and Laserfiche depend upon), and so the mentioned Kofax-only non-shared DLL remains in place in the 32-bit Program Files Capture 'server\bin' folder, and all Registry pointers remain valid and in-place, confounding the troubleshooter. There are a few issues on the Kofax website that include a portion of this error, but then additionally include much more specific error information (the message in this scenario does not, and is largely unrelated to those issues).
Uninstalling Laserfiche (and the MS-Hotfix, if that was included as part of the install) will accordingly, not remedy the problem.
Raymond Cruz of Laserfiche support recommended trying the Kofax VRS-Test or VC-Demo program, which continues to work (it is only used for testing scanner drivers, and does no communications), and so he advises that the problem is therefore not caused by Laserfiche, but is a coincidental Kofax issue. However, no Kofax Capture applications (Admin, Batch Manager, Scan, Validation) will start anymore. This occurred on multiple older-Kofax/newer-Laserfiche clients, but only the ones where Laserfiche had just been upgraded, and occurred within seconds of the upgrade: the other older-Laserfiche/older-Kofax PC clients continued to function normally.
The official recommendation was to upgrade the Kofax scanner drivers, otherwise contact Kofax support and advise them that there is an issue with their Kofax software.
My recommendation is to have those clients not uninstall their old Laserfiche client, but do have those clients instead use Web Access instead of the Laserfiche thick client.
It should also be possible to save the functioning version of that shared library and backup its registry references, and then restore them both afterwards, but because no one would provide any details as to the occurring specifics, and because poring over the event viewer and cross-referencing to the concerned lines in the uninstall/install logs takes more time than may be available, the easiest solution is to just switch to Web Access.
If you encounter this in the field, this may save you some time and grief, because you won't receive any support on this issue. My thanks to the customer that figured much of this out.