Hello
the log you have provided contains the following line:
2015-04-28T10:10:56.985+08:00 [03500 info 'Default'] [diagnosticManager,495] Adding worker log bundle from temp location "C:\WINDOWS\Temp\vmware-temp\vmware-SYSTEM\worker-source-diagnostics-ztj.zip" to server log bundle at "C:\Documents and Settings\All Users\Application Data\VMware\VMware vCenter Converter Standalone\logs\bundles\server-diag-20150428021045-dwhuxz.zip".
HTH. If not, look in "C:\Documents and Settings\All Users\Application Data\VMware\VMware vCenter Converter Standalone\logs" for "vmware-converter-worker-###.log"
Regards