Got a brand new Mega DI Solix 10 g2 control head only today. Decided I would start with upgrading the software to the latest version 3.75...
You have to upgrade to 3.5 first which I did without any issue ... then proceeded to upgrade to 3.75 ... It goes through the update procedure without indicating any error ... but when I check the software version in the Settings-system info screen it still says 3.5

It is creating a log file below is the text.. Anybody else ever see this?

Model SOLIX 10 MDI+ G2 SOLIX_G2
---- Software Upgrade Starting time:2020-09-14_21:08:39----
Validated Source= file://media/sdboot1 success 1, mask = 1
Start Updating SW_CONTROL_HEAD from Version 3.420 to Version 3.500
Successfully Update SW_CONTROL_HEAD to 3.500
issue command /bin/ls /hb/download/solix-unified-app*
--- Software Upgrade End Time 2020-09-14_21:08:39---
Model SOLIX 10 MDI+ G2 SOLIX_G2
---- Software Upgrade Starting time:2020-09-15_01:05:43----
Validated Source= file://media/sdboot1 success 1, mask = 1
Start Updating SW_CONTROL_HEAD from Version 3.500 to Version 3.750
Tampering Detected! Signature does not match Tarball
Failed to upgrade SW_CONTROL_HEAD to 3.750
--- Software Upgrade End Time 2020-09-15_01:05:43---
Model SOLIX 10 MDI+ G2 SOLIX_G2
---- Software Upgrade Starting time:2020-09-15_01:17:16----
Validated Source= file://media/sdboot1 success 1, mask = 1
Start Updating SW_CONTROL_HEAD from Version 3.500 to Version 3.750
Tampering Detected! Signature does not match Tarball
Failed to upgrade SW_CONTROL_HEAD to 3.750
--- Software Upgrade End Time 2020-09-15_01:17:16---
Model SOLIX 10 MDI+ G2 SOLIX_G2
---- Software Upgrade Starting time:2020-09-15_01:33:32----
Validated Source= file://media/sdboot1 success 1, mask = 1
Start Updating SW_CONTROL_HEAD from Version 3.500 to Version 3.750
Tampering Detected! Signature does not match Tarball
Failed to upgrade SW_CONTROL_HEAD to 3.750
--- Software Upgrade End Time 2020-09-15_01:33:32---
Model SOLIX 10 MDI+ G2 SOLIX_G2
---- Software Upgrade Starting time:2020-09-15_01:43:39----
Validated Source= file://media/sdboot1 success 1, mask = 1
Start Updating SW_CONTROL_HEAD from Version 3.500 to Version 3.750
opkg_install_package error
Failed to upgrade SW_CONTROL_HEAD to 3.750
--- Software Upgrade End Time 2020-09-15_01:43:39---
Model SOLIX 10 MDI+ G2 SOLIX_G2
---- Software Upgrade Starting time:2020-09-15_02:07:14----
Validated Source= file://media/sdboot1 success 1, mask = 1
Start Updating SW_CONTROL_HEAD from Version 3.500 to Version 3.750
Tampering Detected! Signature does not match Tarball
Failed to upgrade SW_CONTROL_HEAD to 3.750
--- Software Upgrade End Time 2020-09-15_02:07:14---
Model SOLIX 10 MDI+ G2 SOLIX_G2
---- Software Upgrade Starting time:2020-09-15_03:13:31----
Validated Source= file://media/sdaux1 success 1, mask = 1
Start Updating SW_CONTROL_HEAD from Version 3.500 to Version 3.750
Tampering Detected! Signature does not match Tarball
Failed to upgrade SW_CONTROL_HEAD to 3.750
--- Software Upgrade End Time 2020-09-15_03:13:31---