Problem:

 Error in log:

2021-11-09 13:46:58 main INFO PSUpdaterMain:341 - Moving contents from Source [C:\AE_UAT\Process-Studio-MAIN_STREET_TITLE_AND_INSURANCE_UAT\process-studio\tmp_updater\bkp\lib] to Destination [C:\AE_UAT\Process-Studio-MAIN_STREET_TITLE_AND_INSURANCE_UAT\process-studio\lib]

2021-11-09 13:46:58 main WARN PSUpdaterMain:370 - Destination directory is not empty, deleting all contents

2021-11-09 13:46:58 main INFO PSUpdaterMain:341 - Moving contents from Source [C:\AE_UAT\Process-Studio-MAIN_STREET_TITLE_AND_INSURANCE_UAT\process-studio\tmp_updater\bkp\libswt] to Destination [C:\AE_UAT\Process-Studio-MAIN_STREET_TITLE_AND_INSURANCE_UAT\process-studio\libswt]

2021-11-09 13:46:58 main INFO PSUpdaterMain:341 - Moving contents from Source [C:\AE_UAT\Process-Studio-MAIN_STREET_TITLE_AND_INSURANCE_UAT\process-studio\tmp_updater\bkp\documentation] to Destination [C:\AE_UAT\Process-Studio-MAIN_STREET_TITLE_AND_INSURANCE_UAT\process-studio\documentation]

2021-11-09 13:46:58 main WARN PSUpdaterMain:346 - Backup directory [C:\AE_UAT\Process-Studio-MAIN_STREET_TITLE_AND_INSURANCE_UAT\process-studio\tmp_updater\bkp\documentation] not found to rollback

2021-11-09 13:46:59 main INFO PSUpdaterMain:401 - Updater temp directory deleted.

Solution:

 Problem was with PS folder permissions. Provided permissions to PS directory.

Lib folder was empty, after copying all files to lib directory from new PS issue is resolved.