# Version incompatibility

**URL:** <https://forum.inductiveautomation.com/t/version-incompatibility/3092>\
**Category:** Ignition\
**Created:** [July 13, 2011, 7:58am UTC](https://forum.inductiveautomation.com/t/version-incompatibility/3092 "2011-07-13T07:58:31Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![AlThePal](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/althepal/32/3603_2.png) [@AlThePal](https://forum.inductiveautomation.com/u/AlThePal)\
**Post date:** [July 13, 2011, 7:58am UTC](https://forum.inductiveautomation.com/t/version-incompatibility/3092/1 "2011-07-13T07:58:31Z")

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We have recently upgraded our version of Ignition to 7.2.7. When we deployed the system to our customer (who was still running 7.2.3) we found that they were getting a null pointer exception error for (we think) every table when opening a window. We couldn’t carry out too much testing as we had to fix the problem quickly, which we did by upgrading the customer to 7.2.7.

I wasn’t aware of anything that should stop this working - is there an incompatibility between these versions that would cause this error?

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**Author:** ![Kevin.McClusky](https://avatars.discourse-cdn.com/v4/letter/k/47e85d/32.png) [@Kevin.McClusky](https://forum.inductiveautomation.com/u/Kevin.McClusky)\
**Post date:** [July 18, 2011, 1:34am UTC](https://forum.inductiveautomation.com/t/version-incompatibility/3092/2 "2011-07-18T01:34:33Z")

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Are you saying you developed a project in 7.2.7, and then deployed it to a 7.2.3 gateway by importing the project (or gateway backup)?

If so, I’m pretty sure Ignition isn’t designed to do that. I don’t think _any_ version of Ignition is forwards-compatible (i.e. 7.2.3 _doesn’t_ work with projects created in 7.2.4+, or at least will likely have problems).