cleaned up imports, mobx observable initialization and some compile errors.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/client/views/animationtimeline/TimelineOverview.tsx b/src/client/views/animationtimeline/TimelineOverview.tsx
index 82ac69a3b..928739b53 100644
--- a/src/client/views/animationtimeline/TimelineOverview.tsx
+++ b/src/client/views/animationtimeline/TimelineOverview.tsx
@@ -28,7 +28,7 @@ export class TimelineOverview extends React.Component<TimelineOverviewProps> {
     @observable private overviewBarWidth: number = 0;
     @observable private playbarWidth: number = 0;
     @observable private activeOverviewWidth: number = 0;
-    @observable private _authoringReaction?: IReactionDisposer;
+    @observable private _authoringReaction?: IReactionDisposer = undefined;
     @observable private visibleTime: number = 0;
     @observable private currentX: number = 0;
     @observable private visibleStart: number = 0;