Same problem here in 2017 SP3, looks like a bug with that particular function. Though the SolidWorks portal is down so can't check if there is an SPR for it at the moment! Best report it to your VAR.
You must have tried to add the icon there but not sure why it doesn't get added. If you reset the assembly toolbar (via registry) then it might be pointing to correct location.
Yes i did try and add it but it didn't like it,
I am able to add other buttons such as mate controller and what not.
can you see the button in your command manager.
reg reset toolbar?
If I enable tools toolbar then I can add it on there but not on assembly toolbar
Hi all that are interested.
Solidworks fixed something, mabye, in 2018
The following SPR (SolidWorks Performance Report) status has changed to Implemented.
SR# (Service Request): 1-13980547786
Description: Ability to add 'Magnetic Mate ON/OFF' command to Command Manager
Version: 2018 A1
For more information, visit the VAR Resource Center and select Service Requests (SRs) or Knowledge Base (SPRs).
DS SolidWorks does not guarantee that this SPR fix will be available in the indicated future release of the product since at this time the SPR fix has not completed QA procedures that incorporate all SPR fixes and enhancements into a new version of our product.
Dassault Systèmes SolidWorks Corp. Technical Support