Thank you for confirming and your help.

I've found this:
https://github.com/jrsoftware/issrc/commit/42525f1da5b40218964b3a16f9b75c474d605339
It claims that Inno Setup 6.0.5, which is used since WinSCP 5.17.6, does not support Windows Vista anymore (equivalent of Windows 2008). Strangely it works for me on Windows 2008. But I can reproduce your problem on Windows Vista. In any case, we will have to declare the installer unsupported on 2008 and Vista. Please use the portable package.
I have retrospectively documented this:
https://winscp.net/eng/docs/history?a=5.17.6

Hi,
I did not get any dialogue box (GUI) to select "All users" in "select Setup Install mode". No GUI appears at all when setup is run using 5.17.6 or 5.17.7. It appears ok using 5.17.5.

I've forced the setup to all users using the command line switch. Still no GUI appears and setup does not continue. I've attached latest setup log files with forced all users setup using 5.17.6 and 5.17.7 setup files.

In the log, I see that you are installing 5.17.5 for all users, while 5.17.6 and 5.17.7 for the current user only. Isn't that the difference that causes the problem, rather than the version?

Uninstalled version 5.17.5 and reinstall all ok (log file attached)
version 5.17.6 and 5.17.7 would not install (log files attached)

Thanks for the log, Can you install any other version? (e.g. rerun installation of 5.17.5)
Did you try to uninstall and re-install? (you won't lose your settings).

Hi,

I've attached the log file as private

Can you post the log file?

martin wrote:

Do you mean that 5.17.5 installer works, but 5.17.6 installer does not? What if you add /log=C:\some\path\setup.log to its command-line? Does it produce any log file?

That's correct. Can't upgrade from 5.17.5 to 5.17.6
Did as you saiud and created a log file.

In log file.
Exception message:
Message box (OK):
List item and state item count mismatch
AppMessageBox failed.

Do you mean that 5.17.5 installer works, but 5.17.6 installer does not? What if you add /log=C:\some\path\setup.log to its command-line? Does it produce any log file?

Hi,
I have trying launching setups from and administrator command prompt and "Run as administrator". But does not launch and displays no errors.

Current version I've managed to upgrade to is 5.17.5