I got the same issue and the solution is import SSL certificate of the ASA to Certificate Snap-in:
- Open https:\\asaipaddress
- Export certificate to ABC.cer (up to browsers)
- Start\Run => mmc
- File => Add\Remove Snapin
- Select Certificate \ Computer Account \ Local Computer
- Import ABC.cer to:
- Personal
- Trusted root certification authorities
- Intermediate certification authorities
- Done