ORA-65086: cannot open/close the pluggable database

SQL> show pdbs

CON_ID CON_NAME OPEN MODE RESTRICTED
---------- ------------------------------ ---------- ----------
2 PDB$SEED READ ONLY NO
3 PDB READ WRITE NO
4 TEST MOUNTED
SQL> alter pluggable database test open;
alter pluggable database test open
*
ERROR at line 1:
ORA-65086: cannot open/close the pluggable database

SQL> select pdb_name,status from dba_pdbs;

PDB_NAME STATUS
-------------------- ---------
PDB NORMAL
PDB$SEED NORMAL
TEST UNPLUGGED

之前做过alter pluggable database ... unplug into '...';但不知道unplug into的xml文件到哪个目录了。
可以重新执行一次alter pluggable database ... unplug into '...';
SQL> alter pluggable database test unplug into '/u01/test/test.xml';

Pluggable database altered.

SQL> create pluggable database test using '/u01/test/test.xml' nocopy tempfile reuse;

Pluggable database created.

SQL> show pdbs

CON_ID CON_NAME OPEN MODE RESTRICTED
---------- ------------------------------ ---------- ----------
2 PDB$SEED READ ONLY NO
3 PDB READ WRITE NO
4 TEST MOUNTED
SQL> alter pluggable database test open;

Pluggable database altered.

SQL> show pdbs

CON_ID CON_NAME OPEN MODE RESTRICTED
---------- ------------------------------ ---------- ----------
2 PDB$SEED READ ONLY NO
3 PDB READ WRITE NO
4 TEST READ WRITE NO