graph.db is not a valid database name in neo4j 4.0. That's a folder name in 3.5. Version 3.5 didn't have the concept of named graphs, so basically that was just a directory name.
Try moving it to "graph" or the default which comes with Neo4j 4.0, which is "neo4j"
Naming rules for databases are as follows:
- Length must be between 3 and 63 characters.
- The first character of a name must be an ASCII alphabetic character.
- Subsequent characters must be ASCII alphabetic or numeric characters, dots or dashes;
[a..z][0..9].- - Names are case-insensitive and normalized to lowercase.
- Names that begin with an underscore and with the prefix
systemare reserved for internal use.