Patches and updates
ArcView Network Analyst 1.0b Incremental Patch for Windows
This patch resolves the problem of ArcView Network Analyst "hanging" when loading stops, events, facilities, or sites, collectively known as flags. This problem occurs only when more than ten lines share a common endpoint and the flag falls exactly on the common endpoint.
You must already have installed the ArcView Network Analyst 1.0b update. If you are a Windows user and do not have the version 1.0b update, you can download ArcView Network Analyst 1.0b Update now from this site.