A new version of HelpSystem-Core was added to project The Inbox:
http://source.squeak.org/inbox/HelpSystem-Core-kks.120.mcz

==================== Summary ====================

Name: HelpSystem-Core-kks.120
Author: kks
Time: 2 April 2020, 8:45:13.607196 pm
UUID: 33119c75-ba40-45d4-8ede-7086b7f4bc60
Ancestors: HelpSystem-Core-mt.119

Fetch a topic document afresh from the server if the previous fetch resulted in an 500 error.

=============== Diff against HelpSystem-Core-mt.119 ===============

Item was changed:
  ----- Method: HtmlHelpTopic>>document (in category 'accessing') -----
  document
  
+ 	(document isNil or: [document includesSubstring: '<title>500 Internal']) ifTrue: [
+ 		document := [
+ 				(HTTPSocket httpGet: self url accept: 'text/html') contents
+ 			] on: Error do: [:err | err printString]].
+ 	^document!
- 	^ document ifNil: [document := 
- 		[
- 			(HTTPSocket httpGet: self url accept: 'text/html') contents
- 		] on: Error do: [:err | err printString]]!