Ok, Seems that I found a workaround ...
I just forced the upgrade .. I don't know how can it impact ..
For now, it's working back .
C:\NetXMS\bin>nxdbmgr upgrade -X
NetXMS Database Manager Version 1.2.6
Upgrading database...
Upgrading from version 265 to 266
SQL query failed ([Microsoft][SQL Server Native Client 10.0][SQL Server]Incorrect syntax near the keyword 'WHERE'.):
CREATE INDEX idx_event_log_root_id ON event_log(root_event_id) WHERE root_event_id > 0
Upgrading from version 266 to 267
Upgrading from version 267 to 268
Upgrading from version 268 to 269
Upgrading from version 269 to 270
Upgrading from version 270 to 271
Database upgrade succeeded
C:\NetXMS\bin>
I just forced the upgrade .. I don't know how can it impact ..
For now, it's working back .
C:\NetXMS\bin>nxdbmgr upgrade -X
NetXMS Database Manager Version 1.2.6
Upgrading database...
Upgrading from version 265 to 266
SQL query failed ([Microsoft][SQL Server Native Client 10.0][SQL Server]Incorrect syntax near the keyword 'WHERE'.):
CREATE INDEX idx_event_log_root_id ON event_log(root_event_id) WHERE root_event_id > 0
Upgrading from version 266 to 267
Upgrading from version 267 to 268
Upgrading from version 268 to 269
Upgrading from version 269 to 270
Upgrading from version 270 to 271
Database upgrade succeeded
C:\NetXMS\bin>