I'm trying to update the software on my DSM300 from v4.10 to 4.20 through a e125 MFD and when I insert the MicroSD card and reboot the MFD (DSM300 remains powered when I do this so it's not simultaneously starting up) the installation hangs. Screenshot attached. The DSM300 works normally, but I would like to upgrade the software.
Welcome to the Raymarine Forum Bradley,
The software updates introduced following v4.10 were primarily introduced to improve communications between Raymarine MFDs and a DSM30 or DSM300. Should the system not be reported "DSM Connection Lost" or "No DSM" within the Fishfinder application then it would not be recommended that the DSM be updated with any of the software updates which followed v4.10.
Ok, thanks. I'll leave well enough alone then.