BUG #16812: Logical decoding error

The following bug has been logged on the website:

Bug reference:      16812
Logged by:          Mayur B.
Email address:      mayur555b@protonmail.com
PostgreSQL version: 12.3
Operating system:   Ubuntu 16.04.6 LTS
Description:

Hi,
We started receiving the logical decoding error :
ERROR:  could not map filenode "base/16437/140990927" to relation OID

Database is PG 12.3 and Ubuntu 16.04.6 LTS. There is no "vacuum full" or
CLUSTER happening. What could be other sources of this error?

Thanks