Forced to restart ArcGIS after "successful" script run

Discussion created by rgreenenf on Oct 29, 2011
Latest reply on Oct 29, 2011 by rgreenenf
Good day,

We're using ArcGIS 10 SP2 and have moved a set of modelbuilder and python script tools originally built in 9.3 into the new version. Initially, I changed arcgisscripting to arcpy, but then ran into a showstopper in a new script - ArcGIS would crash on a call from the script to a custom modelbuilder tool. When I converted the new script back to arcgisscripting, it no longer crashed but ended in a 999999 error! So I converted the modelbuilder tool from the v10 Raster Calculator tool back to Single Output Map Algebra and this worked around the error...

However, after "successful" runs of the script I often encounter errors, either:
1. ERROR 000875: Output raster: C:\program files (x86)\arcgis\desktop10.0\scratch\costrst1's workspace is an invalid output workspace. The successful run of the script resulted in the scratch workspace being changed to an invalid path. This can be overcome by fixing up the scratch workspace environment setting.
2. A 999999 error, which can only be overcome by restarting ArcGIS!

Does anyone have any ideas or advice regarding the cause of these errors or ways to overcome the second one? (I did remove a line of python that deleted cursor variables, because in some cases there are no items to iterate through and the variables were not initialized, but I assume this should not be fatal!)

Thank in advance...