Hi
Did you check the consistency between Oracle & SAP DDIC before beginning the upgrade as recommended (DB02 => Diagnostic / missing tables and index) ?
With sqlplus you could check if the table exist (with a command like desc sapsr3.D1GEN )
If it can help here are the DDL commands to create that table and it's index at DB level.
CREATE TABLE "SAPSR3"."D1GEN" ("WHAT" VARCHAR2(30) DEFAULT ' ' NOT NULL ENABLE, "PID" VARCHAR2(33) DEFAULT ' ' NOT NULL ENABLE, "HOSTNAME" VARCHAR2(96) DEFAULT ' ' NOT NULL ENABLE, "TIMESTAMP" VARCHAR2(42) DEFAULT '00000000000000' NOT NULL ENABLE);
CREATE UNIQUE INDEX "SAPSR3"."D1GEN~0" ON "SAPSR3"."D1GEN" ("WHAT");
I've checked on two systems and that table seems to always be empty.
Best regards