Could not parse version constraint error

I am trying to install slim 3 with the composer. I have downloaded the composer, I wrote:composer require slim/slim “^3.0” to the command line and I got an error: could not parse version constraint “^3.0”: Invalid version string.
What am I doing wrong?

Reading, try:

composer require slim/slim:^3.0

Though, I think you’ll find that:

composer require slim/slim

will install what you want…

Thanks for your quick response!
None of those worked, but I have also noticed, that there war another message saying, that my composer was 30 days old.
I am Windows machine, so I had to navigate to ProgramData\Composer\bin folder, open the command line and run : composer self-update
The composer was updated to the latest version, I ran the installation command for slim again and everything went fine!
So the problem was not with the command, but with the composer. :slight_smile: