Hi Everyone,
An issue related to browsing for missing file references has been identified in SW2021 sp4.0. This issue is resolved in SW2021 sp4.1 or by applying a hotfix patch to SW2021 sp4.0. Both update options are now available.

Hotfix:
   The SW2021 sp4.0 hotfix can be downloaded from the KB article S-079256 in our customer portal.

Point Release:
   SW2021 sp4.1 will be downloaded automatically, if you have that option enabled, or is available for manual download at: https://www.solidworks.com/sw/support/downloads.htm

Best Regards,
John