Sorry, I didn't do one of the first steps of troubleshooting, try on multiple machines and see if have the same problem. I tried it on a different machine and it worked. I initially tried it on a laptop connected to a docking station. I disconnected that docking station and tried installing on the same machine again and it too worked. So not sure what is happening when using the docking station for the laptop, but bypassing the docking station seems to have solved the problem though.

So I have deployed about 6 more machines now without docking station like I normally do and this same error message has come up 5 out the 6 times.

Application Mozilla FirefoxESR returned an unexpected return code: 1618

We are installing about 15 different software and Mozilla is somewhere in the middle of the list and is still the only one that keeps giving this error message.

We did not see this problem before until we started deploying the ESR version.

Based on what I can find "Error 1618 is a Windows error that happens when another program is already in the process of being installed."

I'm at a loss.

We just released the 115 ESR. Can you give it a try and see if it has the same error?

Yea, that is what I found for the error as well, but the only software giving this problem is Firefox ESR and we only started having this problem when we swapped the regular install version to the ESR version.

I downloaded 115 ESR to try it. I also found this article: https://support.mozilla.org/en-US/kb/deploy-firefox-msi-installers#

that says the parameter should be /q and not /qn. So I updated the install command for 115 when I uploaded it to MDT.

I have only tried one machine and about to try another, but Firefox gave the same Error 1618.

So although it is windows error, this is the only software doing it and the only one I have ever had this issue with. I understand that doesn't mean it is firefox issue, this was just might starting point to see if anybody else has MDT issues with deploying Firefox ESR.

Just to update. I put the standard .msi file for 114 back in MDT. I made no other changes, I simply just add the application back and readded the installation file.

I gave it the same commands as I was before and which are the same for the ESR version. I also installed all the other software that I was installing for ESR version. So not like there is was more or less software installations.

the 114 installed with no errors.

So it does seem to be something specific with ESR and MDT.

Again this might not be something that is fixed just something that is occuring since we started using ESR as our browser version. We have been using MDT for a long time now, but first times using the ESR install.

MDT deploys the software alphabetically, so Mozilla was always half way in the list of software.

I put aa in front so it would be the first software to install. I have deployed about 4 machines with ESR and not received the error message.

So something with ESR and MDT isn't working quite right if other software tries installing before the ESR install.

Not ideal, but the solution works, just make sure it is the first application to install.

Thanks Mike for responding and attempting to help out. I know this was a special case error.

I am going to mark as resolved again as making it the first application to install seems to be working and is an acceptable solution for us.