Model Builder crashing in ArcGIS10

[sobarim-amin]

Dear All,

I have a problem creating a new model in ArcGIS10.
Whenever I try to create it, ArcMAP crahses. It comes with below error message:
"Encountered an improper argument"

Please advise

[CodyBrown]

I have the same issue. Although since you asked it in 2010 and it's still not answered I doubt I'll get a reply.

[TomSchweich]

Installed ArcGIS 10.2.1 earlier this week. 

Now when I try to start ModelBuilder I get the "Encountered an improper argument."

If I try to edit a model through the context menu, I get "An error occurred within this application. The cause is undetermined." ArcCatalog crashes when I click OK.

Running ArcGIS Basic for Desktop, nothing else.