I am testing version 5 and it works great on Windows 10, but I get an error message on Windows 7 ("Unable to display 'screensaver_name.mp4' It may not be a valid video or movie type for this computer."). That was with a UHD file (size 368 MB). With a Full HD video it was very glitchy/juddery (size 169 MB). The Windows 7 PC is very high spec.
As of November 2015 49% of users used Windows 7, source: https://en.wikipedia.org/wiki/Usage_share_of_operating_systems#Desktop_and_laptop_computers
This kind of makes version 5 useless if it doesn't support Windows 7 as only 10% of all computer users are on Windows 10 (I am sure it is higher now but it seems like people love Windows 7 and are sticking with it).
A friend tried it on his super powered Windows 10 PC and got black screen (maybe 30 seconds) when pressing preview (it worked instantly for me on a much lower specked machine). After a while the screensaver came on for him, this is something we can live with. The Full HD version worked fine for him.
On his 2 Windows 8 laptops both work on one and not on the other. Not great laptops- 3 years old.
As it stands I would need to make a screensaver for Windows 7 using V4 and one for Windows 10 using V5. With a grey area for Windows 8 and low specked machines.
Is Windows 7 going to be fixed for version 5 or will I need to keep using version 4? Also I got loads of errors with version 5 and trying to generate an email error report function doesn't work. For a software which I have already paid for and you want an extra $500, this doesn't bode well.
iScreensaver Designer Log:
1:15:47 0 3 Helper App Crashed: Designer-14816-helper-0
1:18:40 38 3 Unhandled Exception: 0 NilObjectException in cBuilder.MakeInstallerWin%s%oo
1:18:40 8 3 writing log to C:\Users\Admin\AppData\Roaming\iScreensaver\Logs\iScreensaver Designer 5.exe Crash 2016-01-26 011840.log
1:18:57 17364 3 ### CrashReporter: User Chose CONTINUE
1:27:39 15 3 cPicture.GetPicture OutOfMemoryException non-recoverable
1:29:08 43 3 Unhandled Exception: 0 NilObjectException in cBuilder.MakeInstallerWin%s%oo
1:29:08 24 3 writing log to C:\Users\Admin\AppData\Roaming\iScreensaver\Logs\iScreensaver Designer 5.exe Crash 2016-01-26 012908.log
1:29:30 22030 3 ### CrashReporter: User Chose CONTINUE
Please can you let me know what you know regarding the different versions of Windows.
[Eds: edited thread title to be more representative]