From Ian Grieve, Fixed Assets Now Disallows Hyphens In The Asset ID This isn’t the end of the world but it is a bit of pain.
Fixed Assets Now Disallows Hyphens In The Asset ID | azurecurve
General Ledger & FinancialsMicrosoft & the GP Ecosystem
Archived post from 2015. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.