I am using Talend Community edition to create Oracle Connection and using the following steps.
Metadata > Create Connection > Oracle with service Name or Oracle with SID > selected appropriate DB version > Entered all the required details > Check ("Connection failure. you must change Database settings"), please advise.
Note: Installed appropriate driver supporting version of Oracle
Using the same details I am able to connect to DB using SQL Developer. Also using similar approach I am able to connect to different data base as well.
What's oracle DB version you are using? On which talend build version you got this issue? Is there any more error message about your connection failure? Would you mind posting your DB connection setting screenshot on forum? Please mask your sensitive data.