We had tried re-downloading the latest installer as well and got the same message.

Also they were running Windows 10 supporting both 32 and 64 bit applications. As far as I know it not an OS that requires 64 bit in any way, that would be news to me.

I will reach out about getting the log generated.

Gotcha. Yeah, as Miruna said, run it with logging enabled, get the log, and open a support case. It would also be useful to know if the error occurs on more than one machine and/or OS.

That error message is one that we wrote, not the installer surfacing a system-level error from Windows, and for some reason or another the code path that leads to it is getting tripped. The installer code is quite old and it's not the cleverest piece of software in existence - that's part of why we're introducing new ones for Laserfiche 12 soon. The logs will help identify where it's getting tripped up.

We actually downloaded LF 12 first thinking there was a new client but found it is not coming out for a bit, so reverted back to 11. The workstation has version 10 working on it already, we just need to update to 11 so we can connect to Cloud.

I went back in there today, got the detailed logs and opened a support case.

The error details are [PID: 10236] 11:42:46.823  Failed to install Laserfiche Client Suite ARP handler (CombinedARP-x64.msi). Fatal error during installation.

What is ironic is this file, with x64 in the name, when run directly gives the same error message You can not install this on a 64-bit OS.

This is only happening with this one workstation running Windows 10 Pro.

To that last item, the Laserfiche 12 version of the Repository Windows Client will be part of the spring release currently targeted for early April. In the meantime, the 11 Client can continue to be used with both 12 self-hosted and Laserfiche Cloud systems. 

Re: 

What is ironic is this file, with x64 in the name, when run directly gives the same error message You can not install this on a 64-bit OS.

As I understand it, what's likely happening is that the x64 installer is failing (for whatever reason - we're investigating in the case), and then automatically falling back to trying the 32-bit version in the background, which is what's really throwing the "You cannot install this on a 64-bit OS error". 

It is Windows so it supports 32-bit apps

Yes, we're aware.

This isn't about the 32/64-bit attribute of the Laserfiche Windows Client (etc.) software itself. It's a property of there being two different installer bootstrappers that specifically target 64 and 32-bit OS architectures respectively, with those installer bootstrappers coded to only run on the matching OS architecture.

The error message "This MSI cannot be run on a 64-bit OS." is one we wrote, and it appears when the 32-bit installer bootstrapper (again, unrelated to the actual Laserfiche Client software being 32-bit) detects that it's being run on a 64-bit operating system.

To try to restate that in the clearest possible terms, the 32-bit installer bootstrapper has a prereq check function like this:

if ($WindowsOSArchitecture DOES NOT EQUAL "32-bit") {
    Throw error ("This MSI cannot be run on a 64-bit OS.")
}

Ok, I see now. So really this error means very little at all to us as it is the result of the MSI we want to run not working. I checked the other log file generated and found this

MSI (s) (78:9C) [11:42:46:811]: Note: 1: 1708 
MSI (s) (78:9C) [11:42:46:811]: Note: 1: 2205 2:  3: Error 
MSI (s) (78:9C) [11:42:46:811]: Note: 1: 2228 2:  3: Error 4: SELECT `Message` FROM `Error` WHERE `Error` = 1708 
MSI (s) (78:9C) [11:42:46:811]: Note: 1: 2205 2:  3: Error 
MSI (s) (78:9C) [11:42:46:811]: Note: 1: 2228 2:  3: Error 4: SELECT `Message` FROM `Error` WHERE `Error` = 1709 
MSI (s) (78:9C) [11:42:46:811]: Product: CombinedARP -- Installation failed.

MSI (s) (78:9C) [11:42:46:812]: Windows Installer installed the product. Product Name: CombinedARP. Product Version: 11.0.2102.2276. Product Language: 1033. Manufacturer: CombinedARP. Installation success or error status: 1603.