I run the transient study in Fluent and try to open it in CFD Post, but it error Like this. I really don't know How it is happen, I did not interrupt the file during the file was saving.
Am not sure but it seems like you have not been storing files in a single folder. If you have been doing so then the data file might have got corrupted. Try searching manually for the file in the computer and when you find it , move it to folder where you are storing the files related to this particular simulation.
The data is not where it must to be. Or it does not matches with the state macro is pointed to other case that it was moved from its original place. Mohammed can be right also and the data can be corrupted, but in this case are not good news. Try to open in Ensight or Tecplot- both have trial or free with limitations licences.
There are other reason: the file compression is not proper to CFD-post. There are a option in fluent to export to CFD-Post. Try the alternatives. Good look!