BE2010R3 - Job history is not displayed

yesterday 1 backup-job failed and I wanted to check the job-history (e.g. BEX_Sxx_1234.xml) but the window didn't open. 

OS: w2K8R2 latest patched

BE: 2010 R3 with SP4

This server is the primary server, cause he shares the tape-drive with a second server. on the second-server the job-history of

each jobs appears without any problem. Run the

-)diag-utility,

-)repaired the db,

-)rebuild the indices

and

-) repaired the installation of be201r3,

but still no good. You see the second window in the attached pics,

but it want come into foreground (s65.jpg), like normally (s100.jpg).

Jobs are still working, but it is odd to check the jogb-history in the

xml-file instead of the gui.