Flash version

I am using windows 10 64bit version 1903 with latest updates. Server 2.1 beta 2. Why server gives flash version like this?

[2019-09-14 15:44:17.145] [10692] [info]    Received message from 127.0.0.1: VERSION FLASH\r\n
[2019-09-14 15:44:17.146] [4924]  [info]    Sent message to 127.0.0.1:201 VERSION OK\r\n$(build.FlashMajorVersion).$(build.FlashMinorVersion).$(build.FlashBuildVersion).$(build.FlashPrivateVersion)\r\n