I have same problem with error CHSErrorDomain error 1050 on my MBP M1
I try to add new widget target in my existing project. Default widget implementation generates error in canvas.
Strange thing that widget opens successfully on my iMac and MacBook Pro(x86). Same Xcode version is installed on all devices.
Report: https://www.icloud.com/iclouddrive/0VlLAd9Je2GVMMXWhAZVLOI9A#previews-diagnostics-20210316-163845