Having error ORA-01722: invalid number when launching Database | Diagnose | DB Health Check in Toad For Oracle 10.0.0.41 against an Oracle 11gR2 database.
Toad For Oracle 10.0.0.41 doesnt support Oracle 11gR2.
Please refer to the Knowledgebase articleSOL58370.There you will get instructions to download and implementing a patch that addresses various issues with toad 10.0 ( the support of 11R2 among them).
Once the patch is implemented, re test the issue and contact Quest Support if the problem persists.
