I expect the one that caused that exception was the "runtime" one.
Look in the directory: midtierWEB-INFplatformplugins
AND pluginsvrirtruntimeReportEngineplugins
Look for: com.bmc.arsys.oda.runtime_7.6.3
It could be that it's in your ReportEngineplugins folder, but not in the WEB-INF folder, or maybe it's missing altogether.
I don't know where you'd get the right version if they're missing, but maybe if you contact support looking for the jar files it might be possible to get them. I bet you could use the 7.6.04 version of the jar file instead if you could get it.