Existing users of DSM are reporting the following error message after launching the build 7171 of DSM 5.0, which causes it to stop working:
"DesignSpark Mechanical cannot be upgraded when maintenance has expired"
The latest build 7232 fixes this issue and is available for download here: https://www.rs-online.com/designspark/mechanical-download-and-installation
Simply click the "DesignSpark Mechanical V5.0 Win64 bit" download button.
Make sure to uninstall build 7171 before installing this latest update.