Window sometimes appears blank on opening

[KatieZeldaKat]

Rarely, but still often enough to notice, the window will not display any inventions and render as blank:

The log gives this error message:

[invention-manager] TypeError: cannot write property 'items' of undefined

Any time this has happened, an easy solution has been to click on the currently selected tab again so it can reload. This restores the list and works as normal again. As such, it's not a high-priority bug, but one that would be great to get around to for stability.