Cause

For some reason, the Generic Layout has been unloaded by mistake:

Resolution

​There is no possible way to load back Generic FlexiLayout.

However, you can try importing the default document definition from another Invoice project that will contain Generic Invoice Layout.

In ABBYY FlexiCapture:

1. In the main program window, select the menu item Project → Document Definitions...;
2. In the Document Definitions dialog box click the Import... button;
3. In the Open file for import that opens, select FlexiCapture Document Definition Files (*.fcdot) from the Files of type drop-down list and specify the path to the *.fcdot file of another (clean) invoice project. File usually located in Templates folder as on my screenshot below:
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4. The name of the new Document Definition will appear in the Document Definitions list of the Document Definitions dialog box.

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