Failed to prepare 64-bit mode. Error: System Error. Code: 203

One of our customers is encountering the following error message when starting our application protected by XLSPadlock. This is the first customer of several who reported this issue.

Failed to prepare 64-bit mode. Error: System Error. Code: 203. The system could not find the environment option that was entered.

Followed by:

A 64-bit version of Excel has been detected but the application failed to initiate the 64-bit mode. Please contact the vendor. Error code: 8.

See also the actual screenshots, including the Excel version being used.

XLSPadlock-error1

XLSPadlock-error2

XLSPadlock-error3

What is the cause of this error message and how can it be prevented?

Please consider creating a 64-bit EXE file for that customer, and not a universal one.

Thanks for the suggestion. This might be a possible workaround.

However, this feels I am doing one step back with XLSPadlock.
Before, I used to create both 32-bit and 64-bit executables, which was more complicated and error prone.

With a newer version of XLSPadlock this was not necessary anymore, due to the universal executable containing both the 32-bit and 64-bit executable.

What is the reason the universal one does not work?
Is there a way I can make it work, so I don’t have to go back to separate executables?
Is this a bug in XLSPadlock?

It’s not a bug in XLS Padlock itself, otherwise, a lot of other customers would be impacted. This problem generally comes from third-party security software such as antivirus or anti-exploit that can interfere. It can also be a local problem of the computer.

Okay, that sounds plausible.

The customer tells me they are upgrading their desktop environments to Windows 10 and Office 365 64-bit and this error message did show up. I will ask them if they have also upgraded other parts, such as their security software.

Let’s assume that the customers security software interferes with the XLSPadlock protection.

Why would building a 64-bit only version instead of the universal one (your first suggestion) be any different regarding the security software? Don’t get me wrong, I will try this suggestion. But I do need a logical explanation of why our software is failing at the customers place.

The Universal mode unpacks a 64-bit EXE file to the temporary folder if Excel x64 is detected. Some antivirus software dislike having EXE files appear from nowhere in the temporary folder and can trigger false positive alerts or even block the execution of the new EXE file.
A 64-bit EXE only does not need to unpack any other file. So the behavior is less subject to antivirus problems.