This happens when the pcaps do not import properly and get corrupted when imported on commander. In this case you may need to delete the project from commander as well as from system, completely. Make sure you delete the project from all the folders on your system.
C:\ProgramData\Spirent\Avalanche 4.46\user\rmaini\workspaces\Default\database\protocolDB\sapee\pcap\user --> and delete the sapee folder created
C:\Users\rmaini\AppData\Roaming\Avalanche --> Delete your project
Clear anything in “temp” directory. (clear cache Go to Run > %temp% and clear everything in this folder)