You see the error message - "Unable to access the image file" if the access to the image repository failed. This may happen during the following cases:
Follow the steps given below to resolve the issue.
From the computer where you have created the network share, ensure that the firewall/antivirus is not restricting the OS Deployer component from accessing the specific folder.
If your issue persists, write to us at osdeployer-support@manageengine.com