We have answer you on the support ticket you have opened. I will share my answer with the community.
First of all, I want to send you some articles of our Sitefinity documentation connected to Site Sync:
Note that in Sitefinity 5.3 and 5.4 there are some additional steps you need to take.
Several important things:
1. Both sites should be deployed on IIS. Note that you need to grant permission to modify the App_Data folder, by selecting Allow
checkbox of Modify
permission after you have chosen a user (object) in IIS.
2. After you have added the address of the server/s in the Synchronization settings section and before starting synchronizing the site/s please make sure that you are not logged it in this/these site/s.
3. Add http://
in front of your address (servers), when you add them in the Synchronization settings section.
4. In order for site synchronization to work, you must have created a special user on the server that you are going to sync data to. This user must be administrator, but also must be different then the default admin user. During synchronization, this user must not
be logged in. As username and password, enter the credential of this user. For example, on the server you are going to sync to, create a user named sync and assign it to the administration role. During synchronization, make sure this user is logged out.
5. In Site key field, enter a number from 1 to 100 that is unique among all (both source and target) servers that participate in the synchronization.
the Telerik team
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