If Syntax Check fails on 4D Client in the Client/Server environment without any error messages it is possible that the problem is due to the database name length. The files stored on a computer that has used 4D Client (or a merged client) to connect to a 4D Server are located, by default, within the user's Home directory. For example, given a database named "My_Long_Database_Name.4DB" running on a server machine with the IP address 10.96.0.79, the client cache for a user named "Joe" would be located at:
|Mac HD:Users:Joe:Library:Application Support:4D:My_Long_Database_Name.4DB_10_96_0_79_19815
Notice that the folder name is a combination of the database name, the IP address of the server, and the port number (if a non-default port has been used). If the total length of this folder name is more than 32 characters you will see the Syntax Check failure.
This problem only manifests on the Mac OS, not on Windows Clients.
To solve the issue rename the database with a shorter name. To functionally change the name all you need to do is change the name of all associated files (.4DA, .4DB, .4DD, .4DR, .RSR) and in Preferences>Client-Server change the Publication name of the database.