Hi Sonam ,
I think the error is caused by the issue mentioned in this line. ALTER TABLE "myfirstmodule$porequestassets" ALTER COLUMN "productdescriptions" RENAME TO "productdescription"
I recommend that you recheck the column or object that you have named as mentioned above . Since Mendix cannot perform the process, it makes rollback (cancel) for this section. I hope it helps
Regards
Ridvan