Synergy: does the SSL certificate not exist?

I have installed Synergy v1.8.8 on my Ubuntu. It works well as a server until the next reboot. Once I restart the machine, it shows the following errors:

(2020-02-14T11:58:08) ERROR: ssl certificate doesn't exist: /.synergy/SSL/Synergy.pem

The only solution I found so far is to reinstall Synergy. Then it works fine (until the next reboot).

How can I fix it perfectly?