Forticlient "Error unpacking image file"

I have downloaded the Forticlient Online Installer from and try to run it. The image file gets downloaded fine but when it tried to unpack it I get the error

Error unpacking image file 

I've tried to search for an answer but they all point to using the offline installer. I have tried to get the offline installer from Fortinet support but they are being really unhelpful and refuse to give me.

2 Answers

Steps to fix

1. Go to the directory C:\ProgramData (you'll have to allow windows explorer to show hidden items)
2. Look for a file called Applications. No extension, thats the entire filename.
3. Rename it to Applicationsx
4. Try running the Forticlient installer again
5. Go back to C:\ProgramData
6. Delete the directory C:\ProgramData\Applications (this is just used by the Forticlient installer)
7. Rename the file C:\ProgramData\Applicationsx back to Applications

Reason

Forticlient installer unpacks the download file to a directory C:\ProgramData\Application. This conflicts with a file that already exists. Forticlient can't do anythign about it and fails.

This problem would have been easier to fix if Fortinet Customer Support would have just given me the offline installer. They refused to do so because I wasn't a subscriber.

Just to add, I figured it out with help from this youtube video . The video also tells you how to get the offline installer that Fortinet Customer Support refused to give me.

for the above error, you just give the user rights in root drive (c:/) then try to install with admin rights. hopefully, it will install successfully. I have done this activity successfully.