Test with 1.574
println User.getConfigFileFor('UL11251') /build/hudson/users/ul11251/config.xml
println User.getConfigFileFor('UL11251').exists() false
Jenkins.getInstance().getExtensionList(hudson.model.User.CanonicalIdResolver)
Result: [hudson.model.User$FullNameIdResolver@7870a27b, jenkins.model.DefaultUserCanonicalIdResolver@2abb7703]
User.all
Result: [admin, , builder2, readonly, U801841, U803881, U808691, U813361, U814241, U821261, U824001, UEL0WG1, UEL1IM1, UEL1Y11, UEL26G1, UEL2ER1, UEL2ES1, UL07371, UL09891, UL10251, UL10891, UL11131, UL11151, UL11231, UL11241, UL11251, UL11261, UL11281, FRANCESCO FORTUNATO DONATO, UL11421, UL11441, UL11451, UL11461, UL11481, UL11551, UL11571, UL11581, UL11601, UL11611, UL11621, UL11661, UL11751, UL11761, UL11771, UL11791, UL11891, VW05581]
Started to happen to us after rolling back to 1.570. Now some random user account simply "dissapear". We are using the simple permissions matrix and the selected permissions remain, but the user accounts needs to be created again.
Windows Server 2012 R2
Jenkins 1.570