After updating the gateway, some data source can not connect to cluster gateway instances and this message appeared.
I find the error "The target SQL server is unreachable" in internal trace.
Please go to Dataset Settings for the issued dataset, check which gateway is configured for the dataset, if this gateway is offline, please go to the machine which hosts the gateway then start the on-premises data gateway service(if service is stopped), launch the on-premises data gateway application, sign in with your account to make gateway online.
Also please go to Manage Gateways, find the gateway used by this dataset, check if the SQL data source is online as well.
Best Regards,Qiuyun Yu