I am new to both Sketch and Zeplin.
When I am exporting my artboard by pressing cmd + E everything seems to be fine.
Zeplin prompts me to select a project. When I select a project to export into, I get a notification saying "Exported 1 screen(s) to ProjectName".
However a short time later it gives me a error dialog and I cannot see any screen in my Zeplin project.
Here is the error dialog:
Note: My sketch app is in its trial period. But it's functioning well, besides this problem.
Thanks to @zeplin_io's fast support on Twitter I solved my problem.
Adjusting my Mac's Date & Time Pref.s to Auto solved issue.