Config: SyntaxError not being shown in DevTools

Hi there!

Yesterday I updated my iMac to new macOS 10.13 and here are some issues which I came across:

When I add a default window size to the configuration file, the entire configuration scatters and returns to the default settings (fonts, their size, theme, remove all plugins etc.). The same thing happens when I add settings for the Enhanced Tabs Plugin.

I get an error message when loading settings:

The only entry in the DevTools console leads to:

Another thing is my theme: so under the Sierra everything worked as it should. Under the High Sierra however for some reason I lost rounded corners in the application:

I deleted the app, wipe all settings and reinstalled - this did not help. I removed everything again and installed Canary version - problem still occurs.

OS: macOS 10.13 High Sierra
Hyper version: 1.4.7/2.0.3
My config file: https://gist.github.com/kajka/d333f948c65177a6300a25eb3425e427

Start with the linked configuration gist and the DevTools console evidence, then reproduce the settings reset on macOS 10.13 using the reported Hyper versions. Compare the configuration-loading failure with the separate rounded-corners report; done means the reported SyntaxError is surfaced clearly and the affected configuration behavior is covered by a verified result.