Levente Uzonyi uploaded a new version of Monticello to project The Trunk:
http://source.squeak.org/trunk/Monticello-ul.702.mcz

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

Name: Monticello-ul.702
Author: ul
Time: 23 September 2019, 5:42:41.889162 pm
UUID: a4a352f6-efcd-41ce-b716-f490b49229bb
Ancestors: Monticello-ul.701

- disable #useSharedWebClientInstance on Windows by default until the issue is resolved

=============== Diff against Monticello-ul.701 ===============

Item was changed:
  ----- Method: MCHttpRepository class>>useSharedWebClientInstance (in category 'preferences') -----
  useSharedWebClientInstance
        
         <preference: 'Use shared WebClient instance'
                 category: 'Monticello'
                 description: 'When true, use a shared WebClient instance to speed up downloads from MCHttpRepositories. Requires WebClient to be present.'
                 type: #Boolean>
+        ^UseSharedWebClientInstance ifNil: [
+                "The is some issue on Windows, so don't use it there by default. See http://lists.squeakfoundation.org/pipermail/squeak-dev/2019-September/thread.html#203921 for details."
+                Smalltalk os platformName ~= 'Win32' ]!
-        ^UseSharedWebClientInstance ifNil: [ true ]!