First run:

csession CACHE

Then:

w ##class(%SYS.System).InstanceGUID() 

As %SYS is a % package it is available in every namespace.

See related discussion.

What's the problem with specifying default value for  filter control?

CSPSystem.

Workflow REST API is a separate project available on GitHub. You can install it on any version that supports REST, so Caché 2014.1+.

Have you read relevant documentation?

There is also free online course Setting Up Alerts.

You need EnsLib.EMail.OutboundAdapter for that.

What is a "Business Server"?

You shouldn't specify Dispatch Class -it's for REST only.

Maybe add ?CfgItem=Weather to URL.

EnsLib.SOAP.GenericService is a generic service and it does not implement actual services, such as weather but send the request to actual business host -  "Weather BO" in your case.

Your original URL is correct as it references business host name instead of class name

Using JDBC you can call SQL procedures, which are Caché methods.

Additionally, you can access Caché objects and call methods via Caché Java binding.

Can you clarify your post with the code that causes error?

jQuery is a library - a big collection of "classes" and methods you can use anywhere. It makes no assumptions about how your application is built, has no internal DOM tree representation, etc.

Angular JS is an MVC framework - it forces your application to be structured in a very specific way, it manipulates DOM tree of the page according to specified rules. And well, it also provides a big collection of "classes" and methods you can use in your the code, but only the in parts you wrote in compliance with Angular architecture (scopes/controllers/services).

Please consider removing or at the very least modifying the description of:

  intersystems-ru~REST         0.8.0-a  Basic classes for REST web API on InterSystems Cache

It was only relevant with 2014-2015 REST and does not represent best practices for REST APIs in  2016.1+.

There are some problems with many namespace. I found that after I hit about a hundred namespaces on an instance it's time to purge. 50 seems to be the upper limit of easily manageable for me tbh. More, and scrolling in Studio/SMP takes too much time.

Do you have a call to CreateBusinessService somewhere in your code? It allows doing business service calls from non-Ensebble context (by well making current job Ensemble job). It's called like this (from Demo.ZenService.Zen.WeatherReportForm):
 

Set tSC=##class(Ens.Director).CreateBusinessService("Zen Service",.tService)

Where first arguments is a host name of a business service. In your case the error appeared because the first argument is equal to EnsLib.SOAP.GenericService which is not present in currently running Ensemble production. You need to do one of the:

• Check that you're running a correct production
• Change first argument of CreateBusinessService method from EnsLib.SOAP.GenericService to something that exists in current production
• Create business service in production with the name EnsLib.SOAP.GenericService