For simplicity this performs a blocking check for existence of the root and tip uris before restoring a Column View. (Other views are created in a non-blocking way and then removed if their content cannot be loaded but this would be complicated for Column View).
Fixes #2438
For simplicity this performs a blocking check for existence of the root and tip uris before restoring a Column View. (Other views are created in a non-blocking way and then removed if their content cannot be loaded but this would be complicated for Column View).