ORA-00942: table or view does not exist while creating synonym

We are using oracle 11g, The db structure goes like this

We have users CST and FAS. CST user contains a table ST_CAT2, A public synonym 'ST_CAT' has been created for the table CST.ST_CAT2 as s SYS user. ST_ROLE is a role which has given SELECT UPDATE DELETE ALTER privileges on ST_CAT2. ST_ROLE is granted to FAS.

Now, while creating a view as a FAS user,

`CREATE OR REPLACE VIEW "FAS"."EXTERNAL_SR_PENDING_FDB_CAT" ("PROD_ID", "PRODUCT") AS SELECT prod_id, product FROM st_cat;

we are experiencing the error

ORA-00942: table or view does not exist

what could be the cause?