Add warning about build number and 4.x clients compatibilty
See also:
@@ -6,6 +6,14 @@ if ("${BUILD_NUMBER}" STREQUAL "")
set(BUILD_NUMBER "0")
endif()
+if (BUILD_NUMBER LESS 5180)
+ message(WARNING
+ "Setting BUILD_NUMBER to the value less than 5180 will lose compatibility with "
+ "SoftEtherVPN Stable Edition 4.x. Set to a value greater than or equal to 5180 "
+ "if you are likely to connect from 4.x clients."
+ "\nSee also: https://github.com/SoftEtherVPN/SoftEtherVPN/issues/1392#issuecomment-867348281")
+endif()
+
project("SoftEther VPN"
VERSION "5.02.${BUILD_NUMBER}"
LANGUAGES C
