Typically you have to 1st resolve the issue that brought on this condition and after that reconnect manually using plugin context menu explained under. Alternativelly you are able to just restart AmiBroker. Assuming you have got procured historic data for US delisted, and already have the data set up, https://amibrokerdatafeed20852.blogprodesign.com/49934031/data-for-amibroker-secrets