While creating a geometric network on a large geodatabase the procedure stops after some minutes and the following error message is shown.
Build Geometric Network failed.
The object has been deleted and is no longer valid.
File read/write error occurred.
For creating the geometric network temporary files are stored in the temporary directory (%TMP%). Per 1 million features 3 GB has to be expected. If not enough memory is available, the geometric network creation is canceled.
Ensure that enough memory is available in the temporary directory. Maybe the environment variable %TMP% has to be set to another directory.
Other causes might also be possible. For further details please check build.txt also located in the temporary directory.