The GUI App is failing to connect to the selected salesforce Org.
If you are getting an error after selecting the source and the target Orgs and clicking the "Next" button, you probably has a general problem connecting to you Org using the selected SFDX org alias.
- Try to check the connection by running the CLI the force:org:display command in your Terminal / Console and make sure that the connection is not expired and you have a clean console output.
Below is an example of incorrect command output:
This is correct command output:
- One of the most likely reasons, that you have inaccessible orgs stored in the SFDX. For the relevant solution, refer this article: