Gateway error 304 : unable to fin the default datasource?

I have de-install completly ignition and re-nstall the 7.2.9-beta5 (b197)
I create a fresh new project
when I launch the designer i have the error : gateway error 304 : unable to fin the default datasource ?
No specific configuration :
Realtime SQLTags Providers :
default Internal Provider Built-in SQLTags provider

How solve this error ?

i clause the query browser and it’s ok

Yes, the query browser tries to first use the “default” datasource, and the project doesn’t have a default. You can set the project’s default datasource in the gateway, by going to Configuration>Projects.