When I open the python window in either ArcMap or ArcCatalog (ArcGIS 10.1) as soon as I press a key it freezes the entire program and it crashes. It doesn't produce any warning, error, or pop up with info afterwards it just crashes. I tried searching for similar problems through the forum but none of their solutions worked. I installed Service Pack 1 and that didn't solve the problem. I can use IDLE and/or PythonWin to import Arcpy but some custom python tools won’t work. Some of those tools crash it in the same way. Has anyone experienced anything like this or have any idea on how I can get python window to work for Arc 10.1? (I have also tried uninstalling and re-installing ArcGIS 10.1)

  • 1
    What Windows version are you using? Do you have any Python installed other than by your ArcGIS for Desktop installation? Please edit your question to include these details. – PolyGeo Nov 12 '13 at 21:58
  • 1
    Have you tried re-installing ArcGIS? It sounds like a bad installation to me. – RyanKDalton Nov 12 '13 at 22:03
  • 2
    Did you install ArcGIS in its default location on the c:\ drive, or do you have some sort of weird virtualized installation? – Hornbydd Nov 12 '13 at 22:04
  • 1
    Have you installed a new version of numpy? Only numpy 1.6.x will work with ArcGIS, anything else crashes ArcPy (and thus possibly the python window in your case – user2856 Nov 13 '13 at 0:00
  • 1
    Check that, you were right PolyGeo. I had another Python installed on my computer. I swear I looked it over multiple times but I went back and I had Python 2.7.5 installed in addition to Python 2.7 for ArcGIS. Once I uninstalled that everything works perfect. Thanks for your responses all. – bighill Nov 13 '13 at 0:48

I recommend checking whether you have another version of Python installed, besides the one installed by ArcGIS for Desktop.

From the Comments it appears that you did have another Python installed on your computer i.e. Python 2.7.5 installed in addition to Python 2.7 for ArcGIS, and once you uninstalled that everything began to work perfectly.

  • I have the 2.7.2 version of Python installed. I have the 32 and the 64 bit versions, but they are the same version. I am seeing the original problem now - several weird crashes, but if I run Python interactively in ArcMap or ArcCatalog, anything I type causes it to lock up and crash. – CMPalmer Mar 17 '14 at 19:55
  • @CMPalmer my only advice on these symptoms is an uninstall of ArcGIS & Python then reinstall. If that does not resolve it then it is probably a question for Esri support. – PolyGeo Mar 17 '14 at 20:36

I came across this problem after an "IIS Web Platform" installer silently installed a separate version of Python27; uninstalling it of course didn't fix anything. Creating+running a registry patch file (i.e., text file with .reg extension) with the following contents fixed the issue for me:

Windows Registry Editor Version 5.00





[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Python\PythonCore\2.7\Help\Main Python Documentation]


@="Python 2.7"



Same issue just struck me. Python command prompt and idle work but Arc toolboxes crash. I had installed WinPython but it didn't show up on the uninstall list. Weird.

My fix was to manually go through the registry and change all Python paths to the ArcGIS path. Its sort of a one by one thing since each variant of the path is different.

Be careful with multiple pythons.

  • This sounds like a high risk fix to me, so I would certainly advise against it for anyone not comfortable with editing their registry. – PolyGeo Apr 29 '14 at 1:17

I had this issue with ArcGIS 10.4 (which uses Python 2.7.10). I have installed another Python (2.7.15) for testing Mapproxy and it made ArcMap's Python Window crash as soon as I tried to import arcpy.

I had these registry values for local machine:

  • HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Python\PythonCore\2.7\Help\Main Python Documentation (C:\Python27\ArcGIS10.4\Doc\python2710.chm)
  • HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Python\PythonCore\2.7\InstallPath (C:\Python27\ArcGIS10.4)
  • HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Python\PythonCore\2.7\PythonPath (C:\Python27\ArcGIS10.4\Lib;C:\Python27\ArcGIS10.4\DLLs;C:\Python27\ArcGIS10.4\Lib\lib-tk)

It's just as cwa suggested, but I also had to change these as well (for current user) to point to ArcGIS's Python. I used the same values as for local machine.

  • HKEY_CURRENT_USER\Software\Python\PythonCore\2.7\Help\Main Python Documentation
  • HKEY_CURRENT_USER\Software\Python\PythonCore\2.7\InstallPath
  • HKEY_CURRENT_USER\Software\Python\PythonCore\2.7\PythonPath

After these changes Python window works again.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.