Jim, this is a reported bug:
SPR 612491: 'The appearance for this material is different than the existing appearance' applying a material to a part and then adding a new config on Win7
The link you provided doesn't navigate (dead link).
Is this an issue for Windows XP machines only? I've been using SolidWorks since SW 2008, and I have always received this prompt when adding a new configuration to a part that has the "Link Display States to configurations" checkbox cleared (unchecked). So, has SW only recently begun investigating this issue?
Thanks for the heads up on the link, I removed it.
I just pasted the SPR info from the Knowledgebase and it came as a link. Since you do not have access to my Customer Portal info, the link was dead.
Next time I will not hurry so much.
What I should have said in my initial post, is that this issue is more of an annoyance than a bug.
That being said, SW is addressing it as a bug.
First of all: THERE IS A SOLUTION!
It is 2017, 6 years later from the OP, and Dassault Systemes still did not address this issue.
I am using SolidWorks Professional 2017 SP4.1 right now.
I know for sure there are people out there still struggling with it and I know how frustrating this can get.
After digging a lot, I could find some workarounds that really work, which I want to share with you.
It looks like this issue appears only when there are several EXISTING display states and the user decides he wants a NEW CONFIGURATION.
In conclusion, it helps to start with a part TEMPLATE which has several configurations and several display states already made.
This way, the user does not have to make a new configuration: it is already there.
The Second Workaround:
If you forgot to make and use the template mentioned above, when the error message pops up, CAREFULLY follow the following steps:
1. click "Yes" in the message dialog to link the display states to configurations
2. go to any display state and right click and choose Properties
3. UNCHECK "The Link Display States to Configurations" in the Display State Property Manager that appears on the left
4. go back to your Display State Manager on left and DELETE all the useless NEW display states generated by the software
5. enjoy your new configuration together with all of your old display states
The bug is sneaky enough to sometimes fail to show the error message altogether and it goes straight ahead and kills all your hard work wiping ALL of your custom appearances in your custom display states. Wiping without any warning all your custom appearances in say, 10 or 20 different display states, HURTS. A LOT.
Fortunately, though THERE IS a solution for this one too: in order to FORCE the error message to appear and give you the chance to follow the second workaround above, you will need to REMEMBER TO STOP after the second custom display state and go ahead and make 2 new configurations: IMMEDIATELY, ONE AFTER THE OTHER!
The first configuration you'll make will wipe out without warning all your custom appearances.
The second configuration though will show the error message and give you the chance to follow the second workaround above.
As you see, unfortunately this solution is not without loss.
Still, it is much better to lose 1 custom appearance instead of 10. Or 20.
The key here is to stop before making too many display states that you will have to remake.
In the end, I wish to express my hope that Dassault Systemes will eventually address this bug and spare us all of pain and odd workarounds.