Copied all my old wordpress files into the new location
The database structure often changes between versions. The implication is that, for example, one cannot import a pre 3x database into a 3x install and expect it to work.
What was the old wordpress version?
Cant connect to database error
Error connecting to your database is common, but it isn’t necessarily a problem with wordpress itself.
– double check your wp-config.php file settings for the database name, database username and database password. This is where most errors occur.
-Then check that you don’t need to change the database host from “localhost” to something else. You can get that info from your hosting provider.
-Check you have actually created a database with the same database name as is in your wp-config.php file.
-Last, but not least, if all that information is correct your database probably has a problem with it, and you may need to contact your hosting provider if the database server is online / if they have any other problem at their end, or they made any changes to your account, or if there are any limitations/restrictions, if the hosting package is set to Windows and not Linux, etc.
-There are also many threads on this topic on these forums: https://www.ads-software.com/search/Error+establishing+a+database+connection?forums=1
