ORA-01507: database not mounted

ORA-01507: database not mounted
ORA-449 signalled during: ALTER DATABASE DISMOUNT...
Sat Mar 07 23:31:57 2020
System state dump requested by (instance=1, osid=11803 (CKPT)), summary=[abnormal instance termination].
System State dumped to trace file...._diag_11771_20200307233157.trc
Sat Mar 07 23:31:57 2020
SUCCESS: diskgroup FRA was dismounted
CKPT (ospid: 11803): terminating the instance due to error 1507

SQL> alter database mount;

Second case’s is as follows.

Its matching with below bug so please apply patch for this bug.

Bug 17308532 : ORA-1507 DETECTED WHEN STOP DB BY SRVCTL
Affects:

Product (Component) Oracle Server (Rdbms)
Range of versions believed to be affected (Not specified)
Versions confirmed as being affected

11.2.0.4
11.2.0.3

Platforms affected Generic (all / most platforms affected)

Fixed:

The fix for 17308532 is first included in

12.2.0.1 (Base Release)
12.1.0.2 (Server Patch Set)

Symptoms:

Error May Occur
ORA-1507
Stack is likely to include kcblfxl

Description

ORA-1507 from CKPT during shutdown

Workaround
Ignore the error