installation error

I'm a new user and I'm trying to install omeka on my server but it throws the following message:
"Omeka has encountered an error
To learn how to see more detailed information about this error, see the Omeka Codex page on retrieving error messages."
I saw that I must edit the .htaccess file but does not appear in the root folder Omeka
What do I do?

There are two things to check. First, is to make sure that .htaccess really isn't there -- some interfaces like CPanel on servers don't show "hidden", aka "dot", files. So if that's the case, look for a setting that will show those files.

Second, a similar thing sometimes happens with file transfer programs. .htaccess should be there in the original zip file you downloaded, so make sure that your file transfer program that you use to copy the files to the server is also copying 'dot' files.