IsEqualStateTrigger with Enum throwing FormatException at runtime

[leoshusar]

Bringing this issue from here

I've discovered this while using SettingsCard and changing it's ContentAlignment property at runtime by editing XAML.
The SettingsCard uses the trigger like this:

<labs:IsEqualStateTrigger Value="{Binding ContentAlignment, RelativeSource={RelativeSource TemplatedParent}}" To="Left" />

When I set that property before running the app, it works as it should.
But when I live edit it, it doesn't work and logs FormatException.

I found it fails here:

Two more notes:

• I didn't try binding it somewhere
• I'd say this might be occurring in other triggers too, didn't test

I'm running WindowsAppsSDK 1.3