Just attempted updating from the previous version to 5.3 (I think from git_7a49fea-pro), on a Joomla 2.5 installment.
It installed, but the comments (frontpage) didn't load. The comment felt just said "Loading latest comments", with the loader GIF beside it, but that never finished.
So, I reverted to the previous version again, and it works again.

Also, I got some fault messages under the installment:

JFile: :copy: Cannot find or read file: $/home/SITE/public_html/tmp/components/com_comprofiler/plugin/user/plug_usercomments/administrator/language/el-GR/el-GR.plg_plug_usercomments.ini

        JFile: :copy: Cannot find or read file: $/home/SITE/public_html/tmp/components/com_comprofiler/plugin/user/plug_usercomments/administrator/language/en-GB/en-GB.plg_plug_usercomments.ini

        JFile: :copy: Cannot find or read file: $/home/SITE/public_html/tmp/components/com_comprofiler/plugin/user/plug_usercomments/administrator/language/es-ES/es-ES.plg_plug_usercomments.ini

        JFile: :copy: Cannot find or read file: $/home/SITE/public_html/tmp/components/com_comprofiler/plugin/user/plug_usercomments/administrator/language/fr-FR/fr-FR.plg_plug_usercomments.ini

        JFile: :copy: Cannot find or read file: $/home/SITE/public_html/tmp/components/com_comprofiler/plugin/user/plug_usercomments/administrator/language/hr-HR/hr-HR.plg_plug_usercomments.ini

        JFile: :copy: Cannot find or read file: $/home/SITE/public_html/tmp/components/com_comprofiler/plugin/user/plug_usercomments/administrator/language/nl-NL/nl-NL.plg_plug_usercomments.ini

        JFile: :copy: Cannot find or read file: $/home/SITE/public_html/tmp/components/com_comprofiler/plugin/user/plug_usercomments/administrator/language/pl-PL/pl-PL.plg_plug_usercomments.ini

        JFile: :copy: Cannot find or read file: $/home/SITE/public_html/tmp/components/com_comprofiler/plugin/user/plug_usercomments/administrator/language/pt-BR/pt-BR.plg_plug_usercomments.ini

        JFile: :copy: Cannot find or read file: $/home/SITE/public_html/tmp/components/com_comprofiler/plugin/user/plug_usercomments/administrator/language/ru-RU/ru-RU.plg_plug_usercomments.ini

        JFile: :copy: Cannot find or read file: $/home/SITE/public_html/tmp/components/com_comprofiler/plugin/user/plug_usercomments/administrator/language/sv-SE/sv-SE.plg_plug_usercomments.ini