Solved! Go to Solution.
Article - "Mathcad Prime reports an error "(-9) Invalid host" on specific machines even though host-id in the license file matches with host-id displayed in application UI": https://www.ptc.com/en/support/article/CS314914
Go through the steps here
https://www.ptc.com/en/support/creo-admin-troubleshooter/error-code/other-errors/error-9,57
Article - "Mathcad Prime reports an error "(-9) Invalid host" on specific machines even though host-id in the license file matches with host-id displayed in application UI": https://www.ptc.com/en/support/article/CS314914