Hello

Bot profile was added because there are some situations when an action should be done on behalf of the system (site). In the same time any action should be associated with a profile, therefore we decided to generate Bot profile during UNA installation. If you don't like the Bot, you may create your own profile and use it instead of Bot by changing 'System bot profile' setting in Studio -> Settings -> Site Settings.

For example, Bot is used in UNA Notifications app. Each notification should have an author profile. So, a notification with Bot as author will be sent to a profile who uploaded a big video which is failed during delayed transcoding performed in background. 

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Best Regards
Anton