. Update from 8.4.7 to 8.5.1, everything goes smoothly, no errors in installation logs, but then when wasp (UMP) starts, there is just tomcat error message and the whole ROOT folder under wasp/webapps is empty.
UIM 8.4.7 - Upgrade to UIM 8.5.1
not known. Happened only randomly.
Deploy all the UMP probes again into UMP robot will resolve this problem.