Immediate VS2017 15.8.2 crash when going to Options > F# > Advanced, with "A TwoWay or OneWayToSource binding cannot work on the read-only property IsOutliningEnabled of type ... AdvancedOptions"

[abelbraaksma]

Going to Tools > Options > Editor > F# > Advanced crashes Visual Studio immediately.

Debugging it shows the following exception:

System.InvalidOperationException: 'A TwoWay or OneWayToSource binding cannot work on the read-only property 'IsOutliningEnabled' of type 'Microsoft.VisualStudio.FSharp.Editor.AdvancedOptions'.'

Repro steps

After updating my Preview instance from 15.7.x to 15.8.2 Preview, going over the options, it just immediately crashed. I restarted with most extensions disabled, but the same happened.

• Regardless of whether there's a solution open or not
• Go to Tools > Options
• Open Editor > F#
• Click "Advanced"
• BOOM!

Expected behavior

Visual Studio should not crash when going through the Options dialog.

Actual behavior

A crash as described above. After I loaded symbols and started VS with debugger attached, the exception changed (strange):

Even when I set the debugger to break on InvalidOperationException, it doesn't do so, it just comes up with the message above. The stack isn't very useful either:

When I attach post-mortem, I see the error as mentioned above, but the stack shows up empty. It's odd that there's such difference.

In fact, I have no idea how to get more information, but hopefully someone here knows better :).

Known workarounds

None, VS2017 completely crashes, no way to get to these settings in the Options dialog.

Related information

• Windows 7, all updates
• Visual Studio 2017 15.8.2 Preview

[majocha]

Bad merge ate the CLIMutable attribute. It is fixed in nightlies, I think. Somehow the fix didn't make it to 15.8? #4941

[abelbraaksma]

I searched on the error, didn't see it was already reported. Tx!

[cartermp]

Closing as dupe of #5137