Last night I received this error message on all 3 of our Veeam servers. A reboot of one of the servers appears to have resolved it for that server and I'm about to reboot the other servers. I find it strange that this happened to all 3 on the same night. No antivirus on the Veeam servers to cause the issue. It appears to be a Windows issue, but no Windows Updates were installed in the past few days. Anyone have a clue what's going on here?
[14.05.2013 21:08:21] <01> Error Windows cannot open this program because the license enforcement system has been tampered with or become corrupted.\n\n--tr:Failed to initialize agent ( specified agent path: [C:\Program Files (x86)\Veeam\Backup Transport\VeeamAgent.exe], arguments: [ -g"2500-2600" -i"{6ef11653-6cd1-47d4-9172-d52c7bc5d5fd}" -t -l"flush,C:\ProgramData\Veeam\Backup\Agent.MFSYS35.Source.log" -f 25 --vddkLogLevel 1 --maxPendingBlocks 10000 -n -x"{5ebb1a0b-5771-42dd-91b3-8c7df8f30dc2}"])\n--tr:Failed to initialize agent instance ({6ef11653-6cd1-47d4-9172-d52c7bc5d5fd}). (System.Runtime.InteropServices.COMException
Multiple Windows versions. Backup servers are a mix of 2008 R2 and 2008. Guest VMs (items being backed up) are all over the map: 2000, XP, Ubuntu, FreeBSD, 2003, 2008, 2008 R2.
Most of the backups succeeded after automatic retries, except for 2 VMs of one of the jobs, which after rebooting the respective backup server this morning, succeeded as well. Very strange.
Google says that this error is most likely caused by Software Licensing service failure. I think you should not worry much about that as you say that subsequent retries were successful. At least you know who to blame next time it appears.