# Gramplets showing default image for thumbnails \[ new warning message: derived class Glade shouldn't use slots \]

**URL:** <https://gramps.discourse.group/t/gramplets-showing-default-image-for-thumbnails-new-warning-message-derived-class-glade-shouldnt-use-slots/9322>\
**Category:** Help\
**Tags:** bug-filed\
**Created:** [April 8, 2026, 2:53am UTC](https://gramps.discourse.group/t/gramplets-showing-default-image-for-thumbnails-new-warning-message-derived-class-glade-shouldnt-use-slots/9322 "2026-04-08T02:53:53Z")\
**Posts on this page:** 1\
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**Author:** ![SteveY](https://avatars.discourse-cdn.com/v4/letter/s/85e7bf/32.png) [@SteveY](https://gramps.discourse.group/u/SteveY)\
**Post date:** [April 8, 2026, 7:23am UTC](https://gramps.discourse.group/t/gramplets-showing-default-image-for-thumbnails-new-warning-message-derived-class-glade-shouldnt-use-slots/9322/2 "2026-04-08T07:23:16Z")

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Hi @Rick.Allen  
This sounds exactly like a problem that is scheduled to be fixed in the next release.  
It is also reported in these threads

> [@Crash when adding a citation to a marriage event](https://gramps.discourse.group/t/crash-when-adding-a-citation-to-a-marriage-event/9266):
>
> Gramps v6.0.7 Win 11Pro I thought I had a Mantis account but when I tried to login I couldn’t find any login details [Admin: details sent privately.], hence reporting this here. Gramps crashed when adding a citation to a marriage event and generated the dump below but I can’t reliably recreate this crash. User Information: Error Details: 463366: WARNING: imagethumb.py: line 99: Error scaling image down: Unable to marshal str as an array, use .encode() to convert to bytes 501621: WARNING: imag…

> [@Not seeing image previews in Win AIO 6.0.7](https://gramps.discourse.group/t/not-seeing-image-previews-in-win-aio-6-0-7/9289):
>
> I’m using Win AIO 6.0.7 on Win 11 Pro. My version of Gramps knows the media type image/jpeg but I can no longer see previews of images, all I get is a generic icon that looks like: I’ve tried removing the media and adding it again but there is no change. Any clues?

and the planned fix was discussed here  
[Fix imagethumb savev() passing strings instead of lists for array args by dsblank · Pull Request #2204 · gramps-project/gramps](https://github.com/gramps-project/gramps/pull/2204)

@Nick-Hall do you have a date in mind for the next release?

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_[View the full topic](https://gramps.discourse.group/t/gramplets-showing-default-image-for-thumbnails-new-warning-message-derived-class-glade-shouldnt-use-slots/9322)._