Error 0x801F001B

Value: -2145452005 | 0x801F001B | 2149515291

What does it mean ?

ERROR_FLT_ALREADY_ENLISTED  
The specified Transaction Context is already enlisted in a transaction
Value: 27 | 0x001B | 0b0000000000011011

Where does it come from ?

FACILITY_USERMODE_FILTER_MANAGER  
User Mode Filter Manager
Value: 31 | 0x01F | 0b00011111

StackOverflow

Other Errors for FACILITY_USERMODE_FILTER_MANAGER