We have further investigated the issue you are reporting. In order to fix the issue and prevent this from happening again, we need more details about how that happened.
It seems you created a new project and tried to build it, but the build timed out or failed. Then you tried to open it again and it started showing the dialog and message you describe.
Would you, please, verify if this is exactly what happened and which is the AppBuilder client you used?
After we have this information, we will be able to fix the issue for you as soon as possible.
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