When the TE40 is being upgraded from V100R001C10SPC300 to V600R006C00SPC800, the upgrade stops at 60% and fails.
When the TE40 is being directly upgraded from V100R001C10 to V600R006, the upgrade may fail because the version span is too long. The upgrade is successful after the TE40 is first upgraded to V500R002 and then to V600R006C00SPC800.
You are advised to upgrade the TE40 to V500R002 first before the upgrade to V600R006. Note that the TE40 cannot be rolled back to V100R001 after it is upgraded to V600R006.