SRM 4.6 :: "Unable to generate authentication signature" when attempting to register secure connect gateway with SRM 4.6 instance

SEVERE – [yyyy-mm-dd hh:mm:ss EDT] – Bootstrap::sendConfig(): Dell EMC SupportAssist Send Config failed
yymmdd hh:mm:ss : com.watch4net.apg.esrs.webservice.exception.ESRSManagementException: Unable to generate authentication signature
yymmdd hh:mm:ss : at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
yymmdd hh:mm:ss : at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
yymmdd hh:mm:ss : at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
yymmdd hh:mm:ss : at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
yymmdd hh:mm:ss : at com.sun.xml.internal.ws.fault.SOAPFaultBuilder.createException(SOAPFaultBuilder.java:135)
yymmdd hh:mm:ss : at com.sun.xml.internal.ws.client.sei.StubHandler.readResponse(StubHandler.java:238)
yymmdd hh:mm:ss : at com.sun.xml.internal.ws.db.DatabindingImpl.deserializeResponse(DatabindingImpl.java:189)
yymmdd hh:mm:ss : at com.sun.xml.internal.ws.db.DatabindingImpl.deserializeResponse(DatabindingImpl.java:276)
yymmdd hh:mm:ss : at com.sun.xml.internal.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:104)
yymmdd hh:mm:ss : at com.sun.xml.internal.ws.client.sei.SyncMethodHandler.invoke(SyncMethodHandler.java:77)
yymmdd hh:mm:ss : at com.sun.xml.internal.ws.client.sei.SEIStub.invoke(SEIStub.java:147)
yymmdd hh:mm:ss : at com.sun.proxy.$Proxy41.callHome(Unknown Source)
yymmdd hh:mm:ss : at com.watch4net.apg.esrs.util.ESRSConfigUtils.callHome(ESRSConfigUtils.java:232)
yymmdd hh:mm:ss : at com.watch4net.apg.esrs.util.ESRSConfigUtils.sendConfig(ESRSConfigUtils.java:199)
yymmdd hh:mm:ss : at com.watch4net.apg.esrs.Bootstrap.sendConfig(Bootstrap.java:117)
yymmdd hh:mm:ss : at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
yymmdd hh:mm:ss : at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
yymmdd hh:mm:ss : at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
yymmdd hh:mm:ss : at java.lang.reflect.Method.invoke(Method.java:498)
yymmdd hh:mm:ss : at com.watch4net.apg.scheduler.executor.JavaTaskProcessMain.callExecuteMethod(JavaTaskProcessMain.java:538)
yymmdd hh:mm:ss : at com.watch4net.apg.scheduler.executor.JavaTaskProcessMain.main(JavaTaskProcessMain.java:130)
yymmdd hh:mm:ss : INFO – [2022-09-07 hh:mm:ss EDT] – EventNotifier::notifyESRSDetails(): Using Backend Hostname: fqdn_of_primary_backend and Socket: 2020 for notification!
yymmdd hh:mm:ss : Execute method (sendConfig) exited with a failure error code of -1
yymmdd hh:mm:ss : Task supportassist-send-config-centralized-management failed with status 15.