Unable to connect to database error
It would be helpfull if you give some more info. Besides AndyJ's question, also check and post:
- your version of concrete5 (the old server)
- your new version of concrete5 (should be the same !)
- installed add-ons and theme's
- url to the new server (if possible)
Make sure you copied all the packages folders and files
Can you try to enable database debugging in the dashboard on the old server and try to migrate it again ?