[Solved] GNS3 1.3.7 not working | black screen python error while launching


What's GNS3?


GNS3 is a software emulator that is widely used by network professionals to practice real life network scenarios and to study for cisco exams. What I love more about GNS3 is it's community developers. These guys regularly updates this emulator software to add newly released devices and to reflect new standards and more features. More over this is best network simulation software that is available in the market for free of cost.
Let me explain what was this black screen error and how i fixed it!

GNS3 version 1.3.7 black screen Error

Just to explore what's new on GNS3 version 1.3.7,  I downloaded GNS3 1.3.7 from official GNS3 website and installed it on my machine (I'm running Win 8 x86 machine) with all the supporting tools like Wireshark, Solarwinds and Winpcap. But the moment I try to launch my GNS3.exe application it showed up an extremely brief command prompt window, and suddenly the window disappeared within two seconds and then nothing happens. I uninstalled it and reinstalled it again, same issue. I can glimpse some kind of C:/python Failed messages but the command prompt window disappears so incredibly fast I can't even screenshot it.

How to resolve this GNS3 Python error ?

Let's come to the actual point, To capture the error we will have to launch the GNS3 through command line. To launch the GNS3 software through command line, we may have to open command prompt by pressing Win+R and typing cmd and pressing enter key. Refer the snapshot below,



Once you have opened the command prompt window, open GNS3 installation folder by using cd command. In my case it is, cd C:\Program Files\GNS3. Run GNS3.exe from that folder, below snapshot would give you a better idea of what I am trying to say,



Now it will show us the python error which we want to capture for further troubleshooting,


File "C:\Python34-32bit\lib\site-packages\cx_Freeze\initscripts\Console.py", l
     ine 27, in <module>
       File "gns3-gui/gns3/main.py", line 39, in <module>
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2237, in _find_a
     nd_load
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2226, in _find_a
     nd_load_unlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1191, in _load_u
     nlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1161, in _load_b
     ackward_compatible
       File "./gns3-gui\gns3\crash_report.py", line 32, in <module>
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2237, in _find_a
     nd_load
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2226, in _find_a
     nd_load_unlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1191, in _load_u
     nlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1161, in _load_b
     ackward_compatible
       File "./gns3-gui\gns3\servers.py", line 29, in <module>
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2237, in _find_a
     nd_load
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2226, in _find_a
     nd_load_unlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1191, in _load_u
     nlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1161, in _load_b
     ackward_compatible
       File "./gns3-gui\gns3\qt.py", line 43, in <module>
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2284, in _handle
     _fromlist
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 321, in _call_wi
     th_frames_removed
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2237, in _find_a
     nd_load
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 2226, in _find_a
     nd_load_unlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1191, in _load_u
     nlocked
       File "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py", line 1161, in _load_b
     ackward_compatible
       File "ExtensionLoader_PyQt4_QtCore.py", line 22, in <module>
       File "ExtensionLoader_PyQt4_QtCore.py", line 14, in __bootstrap__
     ImportError: DLL load failed: The specified module could not be found.


From the above logs, It is clear that there is something wrong with Python modules. And when I checked for the file "c:\python\32-bit\3.4\lib\importlib\_bootstrap.py" it wasn't there at the specified location.

Hence downloaded the Python 3.4 software from Python official site and installed it in my machine. Guess what? My GNS3 started working fine now.

Try the same on your machine to resolve the issue, You can download the Python software from below link,
https://www.python.org/downloads/release/python-342/
I installed version 3.4.2, but you can try installing any version of Python. Ultimately it should solve the issue.

Also when i checked with my colleagues, I came to know that this python error occurs in other versions of GNS3 like GNS3 1.3.4 and 1.3.5 also. The same steps which are given above is applicable for all the versions & it should resolve the issue.

If you have any queries, Please do let me know through below comment section. Will surely try to help you!

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Hey there! I'm Senthil Kumar Murugesan, An Infrastructure engineer with a focus on Cisco Unified Communications and Hacking. Also I’m happy to mention that I’m a Linux junkie, a Cisco proponent, a Tools fanatic and Script lover. This is a blog, a rambling of thoughts, and a result of technical experiments

1 comments

  1. Awesome post, thanks Senthil

    ReplyDelete

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