I can't install Razer Synapse

I’m having the same issue. I’m following this thread for when Razer replies.

I’ve had the same issue for almost a week and just figured it out last night! I don’t know if the same thing happened to you, but I figured I would share what I discovered just in case. I’m also running Windows 11.

The first time I tried opening the installer, nothing happened (or so I thought). Every time I tried opening the installer after that, I found that error file. After uninstalling Synapse 3 completely and deleting and redownloading the Synapse 4 installer, I found that I didn’t actually get the error file the first time. But every time I tried opening it up after that, I got the exact same error file. When I tried to delete the installer, I got a pop-up that said I couldn’t delete it because the installer was open.

Turns out it was open (running in the background) and somehow not showing up anywhere? I was able to confirm this by finding the process in Task Manager. Once I ended all open Razer processes in Task Manager, the installer popped right up. I had no issues getting Synapse 4 installed after that. I imagine the “permission denied” is popping up because it’s already in use, and the program won’t let you open up a second instance of itself.

Fair warning: Based on a support page I found after the fact, I would advise against uninstalling Synapse 3 completely, as it may mess up your ability to transfer over any profiles.

tl;dr: Closed all open Razer processes in Task Manager and that worked. If you can help it, don’t uninstall Synapse 3, as it may interfere with transferring profiles.

Hope this helps! Let me know if it works for you too!

Same issue here. The problem is that the Razer installer tries to write files to a folder inside C:\Windows\installer\ but that folder doesn't exist on your system and Windows blocks the installer from creating it automatically, so it just fails silently and creates the .err file instead.

The fix is to create those folders manually and grant permissions first, then the normal installer runs fine.

Open PowerShell as administrator and run these commands in order:

Step 1 - Take ownership and grant permissions:

takeown /f "C:\Windows\installer" /r /d y

icacls "C:\Windows\installer" /grant Administrators:F /t

icacls "C:\Windows\installer" /grant System:F /t

icacls "C:\Windows\installer" /grant "%username%":F /t

Step 2 - Create the folders:

New-Item -ItemType Directory -Force -Path "C:\Windows\installer\Razer\installer2\ManifesetCache"

New-Item -ItemType Directory -Force -Path "C:\Windows\installer\Razer\installer2\AppIconCache"

New-Item -ItemType Directory -Force -Path "C:\Windows\installer\Razer\installer2\AppUspCache"

New-Item -ItemType Directory -Force -Path "C:\Windows\installer\Razer\installer2\MediaCache"

Step 3 - Run the normal Razer installer as administrator.

Note: ManifesetCache is Razer's own typo in their code, you have to spell it exactly like that.

First try Step 2 if u get access denied then u have to do Step 1 first

Hi, this helped me. Thank you!

3 weeks and way to many hours spent on trying to install this and find a solution that works for my desktop. This solution did work. So, thank you. Now I wonder why I had no problem installing Synapse 4 on my laptop, just my desktop.