EU4 Paradox Launcher Failure-Not a Valid Win32 Application

[crofo889]

I have been attempting to install EU4 on a new computer, but each time I try to play the game, the installer fails around the 50%, and displays the message C:\\Windows\Installer\MSIE48D.tmp is not a valid Win32 application. This tmp folder does not exist in the File Manager. When I attempt to create a new folder matching the missing tmp, the error message will refer to a new tmp file the next time I attempt to install, so that solution does not work in this case.
I have made sure that my antivirus is not blocking the application and have checked for corrupted files with the System File Checker tool. These are all of the possible fixes I have found online, and none of them have worked
I am able to play the game directly by accessing the .exe file, but without the launcher I cannot access my dlc or mods. I have been playing this game for years, and this is the first time I have ever run into this problem. I would greatly appreciate any assistance from others who have experienced this problem or from the support team.

 

[AndrewT]

This tmp folder does not exist in the File Manager.

To see that folder you'll need to enable View Hidden Items in File Explorer. Then delete its entire contents (NOT the folder itself!); they're only temporary files.

If however it is still not there, you can make it manually.

Good luck!

 

[crofo889]

To see that folder you'll need to enable View Hidden Items in File Explorer. Then delete its entire contents (NOT the folder itself!); they're only temporary files.

If however it is still not there, you can make it manually.

Good luck!

I have already done so, as I saw this piece of advice on a previous thread. The folder referred to by the error message is never there, and changes every time I attempt to download the launcher.
I have repeatedly attempted to create the folder manually, but it changes nothing, as the location referred to by the error message changes to a new location.
Is this an issue of corrupt files, or is the launcher program faulty?

 

[AndrewT]

The folder referred to by the error message is never there,

You mean the C:\Windows\Installer\ folder? You did enable View Hidden Items in File Explorer?

If so, try making that folder manually.

 

[Aryabhata]

I'm having this exact same problem. I found this thread and attempted to create the installer folder. However the new folder never appears. I did recently install a new SSD hard drive and used a bootable USB drive to install a clean windows 11. Other games in Steam and Epic games work. Only the paradox games don't when i launch them through Steam. I get the same message for any of them. I uninstalled them all and reinstalled just one, which can be launched directly from the folder, but not in steam. Sorry if I'm hijacking this thread, but it seems like the same problem. paradox installer can't be found in install/remove programs. I've followed other directions I found where i deleted paradox folders in AppData and relaunched the game. it did not work.

 

[AndrewT]

I'm having this exact same problem. I found this thread and attempted to create the installer folder. However the new folder never appears.

Most likely it is actually there - did you enable View Hidden Items in file explorer?

Also, check you have .NET 3.5 installed. And try these repair tools:

.NET

Microsoft .NET Framework Repair Tool is available - Microsoft Support

Describes the .NET Framework Repair Tool and how to obtain it.

support.microsoft.com

SCANNOW:

Use the System File Checker tool to repair missing or corrupted system files - Microsoft Support

Describes how to use the System File Checker tool to troubleshoot missing or corrupted system files in Windows.

support.microsoft.com