Certs impossible to delete

Hello ,
on a TNC13, I was using openVPN in the last few days internal certs were expired.
I wanted to delete everithing and start to create new CA and cert but that’s impossible to delete.
So i tried to create new CA and cert but then i got new error :
certificate chain could not be verified with specified root CA.

well is there a way to clean all that mess and be able to start a new creation ?