the business data connectivity metadata store is unavailable

[ravir290]

I am using Sharepoint online, not on-premise. When clicking on external content type in sharepoint designer getting error

 the business data connectivity metadata store is unavailable

Please help

[#2]

Same issue here.  Were you able to fix this.  Been dealing with this for weeks 

[#3]

Has anyone gotten answers on this?  @acurtis150