# Fatal error on trying to load program

**URL:** <https://discourse.processing.org/t/fatal-error-on-trying-to-load-program/4537>\
**Category:** Processing\
**Created:** [October 16, 2018, 11:29am UTC](https://discourse.processing.org/t/fatal-error-on-trying-to-load-program/4537 "2018-10-16T11:29:23Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jonnno](https://avatars.discourse-cdn.com/v4/letter/j/e47c2d/32.png) [@jonnno](https://discourse.processing.org/u/jonnno)\
**Post date:** [October 16, 2018, 11:29am UTC](https://discourse.processing.org/t/fatal-error-on-trying-to-load-program/4537/1 "2018-10-16T11:29:23Z")

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about a year ago I used Processing to open DCC++ software. It worked fine  
A week ago I tried to open the same program and get an immediate error  
“an unexpected, unknown and unrecoverable error occurred while opening a new editor window. Please report”  
I have downloaded version 3.4 (previously 3.3). exactly the same  
I downloaded the DCC++ file again with no change…  
I might add that my DCC++ system does not seem to work either but i think i have traced this to a failed arduino uno

Any advice please would be appreciated

jonnn0

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**Author:** ![jeremydouglass](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/jeremydouglass/32/20_2.png) [@jeremydouglass](https://discourse.processing.org/u/jeremydouglass)\
**Post date:** [October 24, 2018, 8:18pm UTC](https://discourse.processing.org/t/fatal-error-on-trying-to-load-program/4537/2 "2018-10-24T20:18:46Z")

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> [@jonnno](#):
>
> I have downloaded version 3.4 (previously 3.3). exactly the same

Well, if it isn’t a change in your operating system, then best guess is that it might be a change in Processing?

> Though this code base is relatively mature and has been tested with the latest version of Processing (3.0.1), it is not as well-commented or documented as the DCC++ Base Station code for the Arduino. [GitHub - DccPlusPlus/Controller: DCC++ Controller for Processing IDE](https://github.com/DccPlusPlus/Controller)

So you could try downloading Processing 3.0.1 to see if that works. Otherwise – did you upgrade your OS?