PHP File Manager

Error while copying from upload/bk/.bk.php to upload/.bk.php

Name	Size	Modified	Perms	Owner
..
arai	Folder	16.08.26 16:52	0777	azureuser:azureuser
bk	Folder	16.08.26 16:42	0777	azureuser:azureuser
UpFile	Folder	22.04.26 11:00	0775	azureuser:azureuser
upload	Folder	16.08.26 18:01	0777	azureuser:azureuser
download.php	2.61 KiB	24.02.17 04:00	0664	azureuser:azureuser
download_2.php	2.61 KiB	24.02.17 04:00	0664	azureuser:azureuser
testlog.txt	977 B	16.08.26 06:34	0777	azureuser:azureuser
upload.php	5.79 KiB	28.04.22 03:19	0664	azureuser:azureuser
upload_2.php	2.09 KiB	28.04.22 03:28	0664	azureuser:azureuser
Full size: 14.04 KiB, files: 5, folders: 4