Upgrade Kaltura

There is no note for backup database and files before the upgrade procedure starts. Is backup process needed or not ?
I have many errors in kaltlog on my current env (kaltura-base-9.19.7-2.noarch
). Is it fixed after upgrade ?

==> /opt/kaltura/log/batch/deletefile-0-2015-03-16.err.log <==
PHP Warning: unlink(/opt/kaltura/web//content/generatedUiConf/23/448/ui_conf_23448409__12.config.xml): No such file or directory in /opt/kaltura/app/batch/batches/DeleteFile/KAsyncDeleteFile.class.php on line 25

==> /opt/kaltura/log/batch/deletefile-0-2015-03-16.log <==
2015-03-16 13:04:26 [167785050] [KJobHandlerWorker->closeJob] ERR: exception ‘Exception’ with message ‘Failed to delete file from disk’ in /opt/kaltura/app/infra/log/KalturaLog.php:82
Stack trace:
#0 /opt/kaltura/app/batch/batches/KJobHandlerWorker.class.php(336): KalturaLog::err(‘Failed to delet…’)

==> /opt/kaltura/log/batch/deletefile-0-2015-03-16.err.log <==
PHP Warning: unlink(/opt/kaltura/web//content/generatedUiConf/23/448/ui_conf_23448409__2.config.xml): No such file or directory in /opt/kaltura/app/batch/batches/DeleteFile/KAsyncDeleteFile.class.php on line 25

==> /opt/kaltura/log/batch/deletefile-0-2015-03-16.log <==
2015-03-16 13:04:28 [690049944] [KJobHandlerWorker->closeJob] ERR: exception ‘Exception’ with message ‘Failed to delete file from disk’ in /opt/kaltura/app/infra/log/KalturaLog.php:82
Stack trace:
#0 /opt/kaltura/app/batch/batches/KJobHandlerWorker.class.php(336): KalturaLog::err(‘Failed to delet…’)

==> /opt/kaltura/log/batch/deletefile-0-2015-03-16.err.log <==
PHP Warning: unlink(/opt/kaltura/web//content/generatedUiConf/23/448/ui_conf_23448409__12.xml): No such file or directory in /opt/kaltura/app/batch/batches/DeleteFile/KAsyncDeleteFile.class.php on line 25

==> /opt/kaltura/log/batch/deletefile-0-2015-03-16.log <==
2015-03-16 13:04:30 [1019698155] [KJobHandlerWorker->closeJob] ERR: exception ‘Exception’ with message ‘Failed to delete file from disk’ in /opt/kaltura/app/infra/log/KalturaLog.php:82
Stack trace:
#0 /opt/kaltura/app/batch/batches/KJobHandlerWorker.class.php(336): KalturaLog::err(‘Failed to delet…’)

2015-03-16 13:04:39 [0.000148] [112.72.13.89] [285943296] [PS2] [kFileSyncUtils::getReadyLocalFilePathForKey] DEBUG: path [/opt/kaltura/web//content/entry/data/0/1/0_785eaxbm_0_r8l09obs_12.jpg]
2015-03-16 13:04:39 [0.000657] [112.72.13.89] [285943296] [PS2] [KExternalErrors::dieError] ERR: exception ‘Exception’ with message ‘exiting on error 17 - image resize failed’ in /opt/kaltura/app/infra/log/KalturaLog.php:82
Stack trace:
#0 /opt/kaltura/app/alpha/apps/kaltura/lib/KExternalErrors.class.php(115): KalturaLog::err(‘exiting on erro…’)