common.apex.runtime.impl.ExecutionException: Unexpected character ('u003C' (code 60)): expected a valid value (number, String, array, object, 'true', 'false' or 'null') at input location
[1,2]"|0x3f13b14b

10:55:06.0 (638787581)|CALLOUT_REQUEST|[43]|System.HttpRequest[Endpoint=https://xyz, Method=GET]
10:55:06.0 (686402163)|HEAP_ALLOCATE|[EXTERNAL]|Bytes:623
10:55:06.0 (686488894)|CALLOUT_RESPONSE|[43]|System.HttpResponse[Status=Service Temporarily Unavailable, StatusCode=503]
10:55:06.0 (686505921)|HEAP_ALLOCATE|[43]|Bytes:443
10:55:06.0 (686523664)|VARIABLE_SCOPE_BEGIN|[43]|res|System.HttpResponse|true|false
10:55:06.0 (686567999)|VARIABLE_ASSIGNMENT|[43]|res|"System.HttpResponse[Status=Service Temporarily Unavailable, StatusCode=503]"|0x1bc0960b
10:55:06.0 (686573201)|STATEMENT_EXECUTE|[45]
10:55:06.0 (686585135)|METHOD_EXIT|[61]|01p5C00000010jE|MyClass.sendRequest(Xys__c)
10:55:06.0 (686652412)|HEAP_ALLOCATE|[61]|Bytes:408
10:55:06.0 (686737328)|HEAP_ALLOCATE|[61]|Bytes:24
10:55:06.0 (686751044)|SYSTEM_METHOD_ENTRY|[1]|JSON.JSON()
10:55:06.0 (686753711)|STATEMENT_EXECUTE|[1]
10:55:06.0 (686764642)|SYSTEM_METHOD_EXIT|[1]|JSON
10:55:06.0 (686776641)|METHOD_ENTRY|[61]||System.JSON.deserializeUntyped(String)
10:55:06.0 (686978112)|METHOD_EXIT|[61]||System.JSON.deserializeUntyped(String)
10:55:06.0 (687006996)|VARIABLE_SCOPE_BEGIN|[78]|e|Exception|true|false
10:55:06.0 (687046591)|VARIABLE_ASSIGNMENT|[78]|e|"common.apex.runtime.impl.ExecutionException: Unexpected character ('u003C' (code 60)): expected a valid value (number, String, array, object, 'true', 'false' or 'null') at input location [1,2]"|0x3f13b14b
10:55:06.0 (687051768)|STATEMENT_EXECUTE|[78]
10:55:06.0 (687053234)|STATEMENT_EXECUTE|[79]
10:55:06.0 (687057739)|HEAP_ALLOCATE|[79]|Bytes:7