With the same PC, I have reinstalled Quartus, changed with a new simpler file.spcinfo and the problem is the same.
I have installed Quartus Lite 18.1 on another PC with window. I can create and compile the project if the project folder is declared under the My documents folder.
But I have a same type of error when I want to delete the project :
Could not delete Makefile.
I ran into this issue in the past and have worked around this by running the Nios II Software Build Tools for Eclipse as Administratior (Right-Click, More--> Run as administrator).
Hopefully this works for you.
Thank you very much for this answer.
Yes, it works, but you need to have your project in the "Documents" folder.
In my case, if I have my project in a root directory, I cannot delete it.
The access isn't full.
Thank you for your help.
I have only a simple administrator account and a user account. What is a superuser permission?
In my job, it is recommanded to use the user account.
I have moved my project folder in "Documents" folder and now it works with your solution.