# Retargeting faults at startup

**URL:** <https://forum.inductiveautomation.com/t/retargeting-faults-at-startup/8252>\
**Category:** Ignition\
**Created:** [April 2, 2014, 3:48pm UTC](https://forum.inductiveautomation.com/t/retargeting-faults-at-startup/8252 "2014-04-02T15:48:56Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![PeterThornton](https://avatars.discourse-cdn.com/v4/letter/p/da6949/32.png) [@PeterThornton](https://forum.inductiveautomation.com/u/PeterThornton)\
**Post date:** [April 2, 2014, 3:48pm UTC](https://forum.inductiveautomation.com/t/retargeting-faults-at-startup/8252/1 "2014-04-02T15:48:56Z")

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I am getting the following error when re-targeting from a system running version 7.5.5 (b1255) to a system running version 7.3.2 (b533):

Error Launching  
Error launching application:  
InvalidClassException: org.python.core.PyObject; local call incompatible: stream classdesc serialVersionUID=-5518487409570819225, local class serialVersionUID = 8745889115762722759

(I’ve attached as image in case of typing errors also!)

I’m not trying to pass any parameters, the retarget is simply of the form:

system.util.retarget(“Project”, “xx.xx.xx.xx:8088:8043/main”)

Any idea what’s going on here?

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**Author:** ![Carl.Gould](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/carl.gould/32/7262_2.png) [@Carl.Gould](https://forum.inductiveautomation.com/u/Carl.Gould)\
**Post date:** [April 2, 2014, 5:00pm UTC](https://forum.inductiveautomation.com/t/retargeting-faults-at-startup/8252/2 "2014-04-02T17:00:02Z")

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Retargeting across the 7.3/7.4 version barrier is a bit rough because of an update we made to our python scripting system.

We “fixed” this in 7.5.2, but to have it work, you also need to update your 7.3 side. Even then, the best-case scenario is that the retarget acts like a straight launch: you don’t get any passed parameters or credentials like a normal seamless retarget.

Please try this: in your 7.3 installation, back up your vision module file, and replace it with this one: [attachment=0]Vision-module.modl[/attachment]

Of course, your best bet is to upgrade the 7.3 Gateway entirely!