I'm using Arc 9.3 and using Network Analyst to create a closest facility layer. I have created the layer and now would like to run analysis using solve. However, every time I open solve in the tool box Arc Map crashes. I'm uncertain why I can not run solve? I have tried it on three other computers and believe it may be my Network Data Set or possibly the properties of my incidents or facilities? I have tried breaking my data into subsets and loading the layers into a new empty map. Any ideas what I should do?