Reason: This could be due to any error which occurred during data collection for any of the modules (messages / disk / problem / historyLog).
Solution:
1. If the error message shows 'Not authorized ' or 'No authority to...' then it may be due to the user account which is used to monitor the AS400 does not have required authority. Please refer the prerequisites for AS400/iSeries in our help document.
2. If the error message shows 'No active collection' under the disk tab, then it indicates the performance collection service is not started or active.
If the performance collection service is not enabled in AS400/iSeries, you need to start it by executing the command STRPFRCOL or perform the following step in AS400/iSeries console window:
GO PERFORM-->COLLECT PERFORMANCE DATA-->START PERFORMANCE COLLECTION.
You can also execute the STRPFRCOL command from AS400/iSeries server monitor page in Admin --> Non-Interactive command option.
3. If the error message shows '/QSYS.LIB/QMHOLHST.PGM: Object does not exist', under history log tab, it is because the System API used to retrieve history log is NOT available for V5R4 or earlier systems. So for these systems we will monitor the message queue(if the user is interested to monitor) as an alternate which can be specified by adding the key 'am.as400.historylogalternative' in AS400Server.properties file (restart Applications Manager after making changes).