When upgrading nuget (to XF3) receive "This collection is read only" VS2017

[tlhintoq]

Description

Same issue as reported in this bugzilla:
https://bugzilla.xamarin.com/show_bug.cgi?id=61113

VS2017 - Trying to upgrade a really simple basic starter app from XamForms2.5 to 3.0. Some packages updated, some don't. For example Xamarin.Android.Support.Core.Utils won't install with Visual Studio error pane reporting "This collection is read-only."

Steps to Reproduce

1. Simple project that is XamForms 2.5
2. Try to update to XamForms 3.0
3. or - try to update all of the existing nugets in the project - some succeed some fail.

Expected Behavior

To actually be able to upgrade Xamarin without it always being a nightmare

Actual Behavior

Nightmare

Basic Information

• Version with issue:
• Last known good version:
• IDE:
• Platform Target Frameworks:
  • iOS:
  • Android:
  • UWP:
• Android Support Library Version:
• Nuget Packages:
• Affected Devices:

Screenshots

Reproduction Link

[PureWeen]

@tlhintoq do you have more info about the type of project 2.5 is or can you include your Simple project (pack ref, pcl, etc....)?

I haven't seen this issue and I upgrade up and down between 2.5 and 3.0 a few times a week

Also I'm curious what version of Visual Studio you are on

[activa]

This was fixed in Visual Studio 15.7.2 (which was released this week)

See also NuGet/Home#6468

[PureWeen]

Closing for now. @tlhintoq hopefully the nightmare is over