@tig said:

Your error message shows that your custom app is using a compiled .SO file.
These types of files will have to be recompiled to ensure they are compatible with the newer SketchUp version...
Speak with the original author, and the fix is in his hands...

OK thank you for the advices , I'll speak to them and try to fix it. Thank you!

@yienh said:

@tig said:

Without knowing the details of your 'in-house' program it's impossible to tell.
However, when SketchUp starts it must load some files [probably from you Plugins folder] to set things up...
If you know what these are you should be able to copy them into your newer Sketchup's Plugins folder ??
Then the newer SketchUp version will try to load this too...
As it is 'in-house' why can't you ask whoever made it what to do ???

Yes, I copied them to 21's plugin , but Ithink there's something different between 18's and 21's.
Here are the notifications when I start sketchup. There are load problems , but 18's also have them,too. 18's can work on the Sketchup,there can be icons on the toolbar, but 21's just not show up.

Excuse me..., because they don't work on it anymore... so they also don't know why is it,I'm just wondering if someone is also working on the plugin developing.

@tig said:

Without knowing the details of your 'in-house' program it's impossible to tell.
However, when SketchUp starts it must load some files [probably from you Plugins folder] to set things up...
If you know what these are you should be able to copy them into your newer Sketchup's Plugins folder ??
Then the newer SketchUp version will try to load this too...
As it is 'in-house' why can't you ask whoever made it what to do ???

Yes, I copied them to 21's plugin , but Ithink there's something different between 18's and 21's.
Here are the notifications when I start sketchup. There are load problems , but 18's also have them,too. 18's can work on the Sketchup,there can be icons on the toolbar, but 21's just not show up.

@tig said:

You can install copies of extensions/plugins in different versions of SketchUp.
However, you need to do this manually, as the versions do not 'communicate' with each other...

Thank you for replying this topic, but the plugin I have is a company's goods and I have the source code, my problem is "This plugin was programmed in version2018 but I want to use it in version2021 and even further. Can I just modify the code so that I can fit the version?"
Thank you again for replying!

I have confronted with a plugin I have for woodworking.
It's working on version2018,but if I change to version2021,the icon just don't appear.
Should I work on Ruby program or WHAT caused this problem ?

Sorry I didn't ask it right , I have the code of this plugin, but I want to modify the plugin programmed in 2018 so that it can also be used in version2021....and so on,is there any code about this to modify?

thank you all