IPSec Site to Site Preshared key - no such file or directory

Hi community,

I'm trying to setup site to site IPSec connection with a preshared key between two XG 125. Both are running SFOS 18.5.2 MR-2-Build380.

I setup the connection according to https://docs.sophos.com/nsg/sophos-firewall/18.5/Help/en-us/webhelp/onlinehelp/AdministratorHelp/VPN/SiteToSiteVPN/VPNCreateSiteToSiteIPsecVPN/index.html#add-a-firewall-rule_1

I can active the IPSec connectin on both sides but when trying to connect from Branch office I simply get the error message IPsec connection could not be established.

Checking the logs I find this in strongswan.log:

2022-01-22 23:16:14Z 26[APP] [COP-UPDOWN][STATUS] (db_status_update) conn_name: Wiesham_to_HQ count: 0
2022-01-22 23:16:30Z 09[CFG] rereading secrets
2022-01-22 23:16:30Z 09[CFG] loading secrets from '/_conf/ipsec/ipsec.secrets'
2022-01-22 23:16:30Z 09[CFG] get_nsg_context tblvpnconnection:ipsec
2022-01-22 23:16:30Z 09[CFG] expanding file expression '/_conf/ipsec/connections/*.secrets' failed
2022-01-22 23:16:30Z 10[CFG] rereading ca certificates from '/_conf/ipsec/ipsec.d/cacerts'
expanding file pattern '/_conf/ipsec/connections/*.conf' failed: No such file or directory
2022-01-22 23:16:31Z 18[CFG] vici initiate 'Wiesham_to_HQ-1'

This seems to me that there are missing config files. When are they created?

What do I have to do in order to fix this?

Any help would be highly appreciated!

Thanks,

Gernot