archive command repeatly failing for one particular file I am seeing many pg_log files full of following errors

2019-07-08 00:04:06 CEST DETAIL:  The failed archive command was: copy "pg_xlog\000000010000002100000025" "D:/Programme/OmniBack/server/db80/pg/pg_xlog_archive/000000010000002100000025"
2019-07-08 00:04:07 CEST LOG:  archive command failed with exit code 1
2019-07-08 00:04:07 CEST DETAIL:  The failed archive command was: copy "pg_xlog\000000010000002100000025" "D:/Programme/OmniBack/server/db80/pg/pg_xlog_archive/000000010000002100000025"
2019-07-08 00:04:07 CEST WARNING:  transaction log file "000000010000002100000025" could not be archived: too many failures
2019-07-08 00:05:07 CEST LOG:  archive command failed with exit code 1**


postgres.conf having settings

checkpoint_segments = 256
wal_buffers = 256MB
wal_level = archive
archive_mode = on
port = 7112
work_mem = 128MB
shared_buffers = 512MB
effective_cache_size = 32719MB
listen_addresses = '*'
logging_collector = on
log_line_prefix = '%t '
archive_command = 'copy "%p" "D:/Programme/OmniBack/server/db80/pg/pg_xlog_archive/%f"'**


I have checked pg_xlog folder for this file. This file is not present in pg_xlog but in pg_xlog\archive_status with following permissions

pg/pg_xlog\archive_status\000000010000002100000025.ready 

KDLF\adminkdlf:(I)(F)
VORDEFINIERT\Administratoren:(I)(F)
NT-AUTORITŽT\SYSTEM:(I)(F)
VORDEFINIERT\Benutzer:(I)(RX)


My disk is getting full. Please tell why this issue is coming because of this others logs are still not archived. I am not sure if I am missing something here.
If the file is not in pg_xlog, but there is a .ready file in archive_status, then somebody must have removed that file, which is why archival is failing.

Temporarily set archive_command = '/bin/true' until the view pg_stat_archiver indicates that PostgreSQL is happy again, then set the parameter back to its original value.

Perform a new base backup immediately after that.

You won't be able to recover across the point where you have no WAL archives.

Try to find out which of your administrators is stupid enough to delete files from the data directory and send him or her to a PostgreSQL course.