1. Open a new Excel sheet and enter data.
2. Save the new Excel sheet as .csv on the USB stick directly.
3. Prompt to enter the password and confirm password.
4. Click OK on the message and enter the password and confirm password again for the .CSV extension.
When you try to re-open the .CSV file, the data you enter is not available or gets corrupted.
This issue has been fixed in the release Symantec Endpoint Encryption Removal Storage version 8.2 MP2 HF1.
Please upgrade to that version or later to fix this issue.
Follow the below article to perform the upgrade.
How to upgrade the SEE Management Server.
Microsoft Office 2007 with Symantec Endpoint Encryption 8.2