Unable to connect to SQL server instance

Desktop version : 4.1.1

I was trying to import a single database from a SQLServer that has multiple databases. But ETL tool kept creating a mapping for all the databases in the SQL server even when I specify the correct DB in the connection. As it is inconvenient to exclude around 4000 tables that are belong to other DBs from the mapping I installed a SQLExpress as an instance "localhost\SQLEXPRESS" and restored the source database I was interested to SQLExpress. Then I created a connection successful.

But when I click start mapping on ETL tool gives below error:

COMMAND: java -cp "C:\Users\Inclute.Neo4jDesktop\graphApps_global\neo4j-etl-ui/dist/neo4j-etl.jar;C:\Program Files\Microsoft JDBC DRIVER 8.4 for SQL Server\sqljdbc_8.4\enu\mssql-jdbc-8.4.1.jre8.jar" org.neo4j.etl.NeoIntegrationCli generate-metadata-mapping --rdbms:url "jdbc:sqlserver://localhost\SQLEXPRESS:1433;databaseName=xxxxxDB" --rdbms:password "xxxxx" --rdbms:user "xxxxxlabsvc" --schema "dbo" --output-mapping-file "C:\Users\xxxxx\AppData\Local\Temp/mssql_xxxxxDB_dbo_mapping.json" - Command failed due to error (IllegalArgumentException: Illegal character in opaque part at index 27: jdbc:sqlserver://localhost\SQLEXPRESS:1433;databaseName=xxxxxDB). Rerun with --debug flag for detailed diagnostic information.

I would appreciate if some one could help me how to connect to SQL instance or how to create a mapping to a single database in a SQL Server that has multiple databases