Yeah it is not compatible, usually when you work with PT is great if you include the version on the name of your project, like: Network 8.1.pkt This will help you to not run into that issue, it is rarely the problem with your file being corrupted.You...
The issue is when the cisco packet tracer is updated from 8.0.1 (example) to 8.0.2. The old file you worked on 8.0.1 wont work on the 8.0.2 It is just something that Cisco needs to fix. You can work on the old file by downgrading the Packet tracer. o...