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Participant
June 16, 2025
Answered

CEP Plugin : IOError when loading PlugPlugExternalObject in 20.4

Hello,

 

We have an InDesign plugin on the marketplace and all our MacOS users who updated to Indesign 20.4 has an error at plugin launch "IOError: I/O error".
The error comes from this line that has been in the plugin for 8 years without any issue:

xLib = new ExternalObject("lib:\PlugPlugExternalObject");

From what I found, this is still the standard way to load this library.

I've tried to remove the \ but it did not change anything, at least when building locally.

 

Does anyone else have the same issue since the update ?
Is it a known issue ?

Abhishek Rao
Abhishek RaoCorrect answer
Community Manager
June 25, 2025

Hi everyone,

 

Just wanted to share an update that the issue with PlugPlugExternalObject and the resulting I/O error has been addressed in the InDesign 20.4.1 update. If you haven't updated yet, we recommend giving this version a try.

 

Please let us know if the problem persists after updating, we'll be happy to assist further!

Abhishek

3 replies

Abhishek Rao
Community Manager
Abhishek RaoCommunity ManagerCorrect answer
Community Manager
June 25, 2025

Hi everyone,

 

Just wanted to share an update that the issue with PlugPlugExternalObject and the resulting I/O error has been addressed in the InDesign 20.4.1 update. If you haven't updated yet, we recommend giving this version a try.

 

Please let us know if the problem persists after updating, we'll be happy to assist further!

Abhishek

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Community Expert
June 17, 2025

Hi @a.cavoleau,

Seems this is getting reported by others as well. See https://community.adobe.com/t5/indesign-discussions/csxs-event-warning/m-p/15372744#M628319

-Manan

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-Manan
Charu Rajput
Community Expert
Community Expert
June 16, 2025

Hi @a.cavoleau 

This is a known bug in the latest version of InDesign and has already been reported. Unfortunately, it has reappeared in the most recent release.

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Best regards