You should consider the listed issues when performing an upgrade.
Upgrading to release 10.3.4 requires a new activation. See Activating D3 to activate the D3 license for a multi-user environment.
If a previous release of D3 has been loaded, D3 installation files might still be present in the /tmp directory. These are the files loaded from media with the tar command. These files must be removed before a new release of D3 is loaded.
To check for and remove old D3 files, enter:
cd /tmp ls -l D3* rm D3*
You must obtain a new copy of any third-party product that uses assembly code. For example, Accuplot, PowerComm, Jet, and so on. Third-party products that use assembly code must be reassembled with the D3 10.3.4 assembler. All custom code needs to be reassembled.