I'm using MAMP Pro to develop a few different websites offline.
The first one was a fresh WP install, and I followed a tutorial and managed to get it working perfectly, I can go to 'dev.mynewwebsite.com:8888' and it goes to the website, and also go to 'dev.mynewwebsite.com:8888/wp-admin' and it successfully takes me to the WP login etc.
However, I have an already-live WP website I want to improve in an offline environment. I downloaded the entire folder structure via FTP through Cyberduck and added it to a new folder in MAMPs htdocs. I then downloaded the database, and imported it and changed all the necessary URL refs (as detailed here, though in reverse http://wp.smashingmagazine.com/2011/09/28/developing-wordpress-locally-with-mamp/ ) and altered the 'wp-config' file with appropriate mysql user and password.
When I go to 'dev.myotherwebsite.com:8888' the page opens, but appears to not be reading the CSS file at all, so looks insanely ugly. And if I try to go to 'dev.myotherwebsite.com:8888/wp-admin' (exactly the same as with my other one) I get a 'server error' and no way of accessing the WP admin pages etc.
I have a feeling that some references must not be set properly, and files aren't being included properly, but I don't know how to track down the problem.
Any suggestions from you fine people?
Thank you for your time!