2475146 - SUM : logon via SAP Host Agent is failing "Unable to locate the requested resource" or "<hostname>\<sidadm> is not authorized to process the operation ExecuteOperation"

Starting Software Update Manager (SUM) with SAP Host Agent fails with error while launching SUM URL on browser.

Browser shows following error:

Not Found
Unable to locate the requested resource

Error from log file /usr/sap/hostctrl/work/sapstartsrv.log:

[[Thr 140461600352000] *** ERROR => ConnectContext for /lmsl/sumjava/<SID> failed [Operation [id=901B0E82D84A1EE6B4EB8F9DD0DF4B2A] 
terminated with errors : 9 ()
] [HTTPProxyHan 711]

OR

"Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental"

DIR_SAPHOSTAGENT\work\sapstartsrv.log shows below error

[Thr 4268] Thu Mar 26 20:14:32 2020[Thr 4268] HTTPHandlerManager : HTTP Handler found for /lmsl/sumabap/<SID>/manual_actions?xsl=0&_=1585251362394[Thr 4268] *** WARNING => Invalid file 'runnings.commands\005056A59D061ED79FB012010D7D4108_0_6684_4294967294' [PersistentOp 343][Thr 4268] *** ERROR => Permission denied: user <hostname>\<sidadm> has no permission for operation 005056A59D061ED79FB012010D7D4108 [OperationPlu 326][Thr 4268] *** WARNING => Invalid file 

NOTE: Above is just an example and it could show a different id.

\ is not authorized to process the operation ExecuteOperation""> Read more...

• Software Update Manager (SUM)
• SAP NetWeaver AS ABAP
• SAP NetWeaver AS JAVA

SAP NetWeaver 2004 ; SAP NetWeaver 7.0 ; SAP NetWeaver 7.1 ; SAP NetWeaver 7.2 ; SAP NetWeaver 7.3 ; SAP NetWeaver 7.4 ; SAP NetWeaver 7.5 ; SAP Solution Manager 7.2 ; SAP enhancement package 1 for SAP NetWeaver 7.0 ; SAP enhancement package 1 for SAP NetWeaver 7.3 ; SAP enhancement package 2 for SAP NetWeaver 7.0 ; SAP enhancement package 3 for SAP NetWeaver 7.0

upgrade, SUM, not authorized, ExecuteOperation, Forbidden, 403, Unable to locate the requested resource, runnings.commands, internal Server Error, Status 500, SUM, SL Common UI, Software Update Manager, SAP host agent, HTTP 404, Webpage cannot be opened, Not Found, Unable to locate the requested resource, 127 (null), Status 500, WshShell.RegRead, pam_authenticate, sapuxuserchk, sapstartsrv, lmsl, sumabap, sumjava, sapstartsrv.log, dev_saphostexec, logon type, ConnectContext, SAPUp, ExecuteNextCommand, SendError, localhost, 127.0.0.1, loopback, starting sum , KBA , BC-UPG-TLS-TLJ , Upgrade tools for Java , BC-UPG-TLS-TLA , Upgrade tools for ABAP , Problem