Hi,
If the issue is related to not been able to load/play the entire length of the file, try the following:
1. From WavePad, select the Options menu > Audio tab > "Audio working folder" section, check mark the "Use this specified folder" box and copy the folder path.
C:\Users\YourUserName\AppData\Roaming\NCH Software\WavePad.
2. Paste the path on your windows folder explorer, this will open the Cache content files.
3. Delete all files within this folder.
4. Close WavePad and re open it again.
5. Re load the file and confirm.
Best regards,