First of all, it should be determined whether there is a single call or a general problem. While making this determination, it should be checked whether the call can be downloaded and listened with the save button by a user authorized to download the call. If the call can be downloaded but cannot be listened to, there may be a version-based bug. If the call cannot be downloaded with the save button and it gives an error that it cannot access the path, it may be that access to the path where the audio files are kept may have been cut off, or the information of the call may have been recorded, but the physical form could not be taken into the system.