I want to connect to an old Oracle9i Release 9.2.0.4.0 database with SQLDeveloper 21.4.3 and I followed this answer

Maybe ask Oracle support to get an older version of SQL Developer.

CodePudding user response：

Oracle provided me a link for older Instant Client Versions. Version 11.2 works fine with SQLDeveloper 20.2. SQLDeveloper 21 only supports client versions 19 and higher.