Every time I launch Unity 5 I get this error:
I have checked the path and that file doesn’t exist. I tried to launch as administrator and there’s not error, but it appears again when launching the proper way. I use windows 7.
Unity works fine (as far I know), but it is annoying to get this message every time I launch the app.
Same to me …
So, try and write a file yourself into that folder. Just save the contents of a Notepad.exe file there. The error message says that Unity isn’t allowed to write there. If you can, then we at least know it’s not a system-wide permissions problem.
I saved a document from Word into this folder and it worked. I have permission to write.
Okay, I changed the read/write properties of Unity_v5.x.ulf to give all users full access. The error message disappeared 
Yes, changing the file permissions solves the problem. Thanks.
I have this problem to and I can’t find that folder anywhere… please someone help me! and i don’t seem to find how to change the permission on the program either! I’m new to unity 5 so please help
The folder “C:/ProgramData” is a hidden folder, if you don’t find it, you can change the explorer settings to make hidden folder visible. http://www.sevenforums.com/tutorials/394-hidden-files-folders-show-hide.html
Go to C:\ProgramData\Unity (hidden folder)
To Unity_v5.x.ulf file, right click > properties > security tab
Edit > select your user > Allow full control > Apply
I seem to be having the same problem on my mac, but changing the permissions doesn’t work.
My 4.6.x install crashes when I try to return the license, so there must be something really funky going on.
I was testing out the 5.0 open betas and RC’s just fine, so it’ getting incredibly annoying.
I don’t have the same problem with my PC install.
To: Unity Engineer:
I think is a Unity Bug(Update: In my case is not unity bug). I has the same problem.
I notice that when I installed Unity 5.0.2 it ask me to install to the Administration Programs folder and not the normal User programs folder confusing user. And i change path putting it probably in a incorrect place since my pc is 64 bit. C:\Program Files\Unity5
Hope this can help.
Probably worth submitting bug report with this information, which will mean the QA guys get to see it. If you post the bug number here, I’ll poke the QA guys.
Try to restart Windows for 4 times !
When i use the software samsung data migration to clone my disk and pas to a much bigger, it make a clone of my ssd . I was passing from a small C: to a bigger one.
In the first start, looks like the name of the pc is the same but not the user. Looking inside a file, right click > properties > security tab , the user “me…” now is call “user” so is not a Unity problem. The general user name is correct but not the internal system user name. I’m not a Windows expert. Also other programs as for example antivirus and Allgoritmic B2M, Fuse etc are asking me the S/N at the first start. After restarting my system from a complete shutdown and 4 restart, the user name is correct and all runs.
I have the same problem but i’m using Mac not a pc anyone got any tips on how to fix this error?
Are you logged in as an Admin user?
I updated to Windows10 and went through the same trouble… even after checking the writing permissions on that file in the said folder, it wouldnt work… I finally solved the problem by simply replacing the file manually by the ULF file I generated on the Unity page without asking Unity itself to do so. Everything worked fine again after (y)
Just installed Unity5 on my Mac - same error - I made a folder, wrote a text file, adjusted permissions… but no luck. Unity5 always fails to setup the license file with the same error:
Failed to write license file
Failed to write “/Library/Application Support/Unity/Unity_v5.x.ulf”. Please verify you have write permissions to this file.
At which point, Unity will not start - so no Unity 5 for me 
Managed to solve it today - just run with sudo from the command line…
sudo -b /Applications/Unity/Unity.app/Contents/MacOS/Unity
Once the file was created, I can run Unity 5 normally.
How did you do that?
