You may be prompted with the following error below when you wish to start a VM that the .vdi files have been deleted. If you want to read more on the Windows system you can read these: How to prevent Windows Users from changing the Screen Saver via the Registry Settings, How to Upgrade Windows 11 Pro to Enterprise and vice Versa, How to install Windows 11 on HyperV, How to Install Windows Admin Center on Windows 10 & 11
Fix failed to open session for the virtual machine GNS3
Expanding “details,” more insight into the error will be described. This error is self-explanatory. Therefore, I will proceed with my recommendations (solutions) below.
Solution
Restore the deleted .vdi files and attach them to the GNS3 VM, delete the GNS3 VM from Oracle Virtualbox and delete all associated files, and have a new GNS3 VM recreated.
I hope you found this blog post on fix failed to open session for the virtual machine GNS3 helpful. Please let me know in the comment session if you have any questions.