Upgrade from 11.5.10.2 to R12.1.1

Hi,
We 've ran rapidwiz to upgrade from 11.5.10.2/10.2.0.5  to R12 /10.2.0.5 this error occured :

Database ORACLE_HOME environment file passes instantiated variables test:
      File = /test/d01/oracle/db/tech_st/11.1.0/MIGR_mig01.env
   TNSNames SQL*Net file passes instantiated variables test:
      File = /test/d01/oracle/db/tech_st/11.1.0/network/admin/MIGR_mig01/tnsnames.ora
   RW-50016: Error: - APPL_TOP environment file was not created:
      File = /test/d01/oracle/apps/apps_st/appl/MIGR_mig01.env   ADOVARS environment file passes instantiated variables test:
      File = /test/d01/oracle/apps/apps_st/appl/admin/adovars.env
   APPSCONFIG passes instantiated variables test:
      File = /test/d01/oracle/apps/apps_st/appl/admin/adconfig.txt