Curious If anyone else is having this exact issue using VOSS 8.3 in GNS3, write mem, save config will not save a valid config file, If you reboot the virtual appliance it boots up in a defaulted state.
The following fixes the issue and allows you to save config with the command save config and boot the box from the config file you saved:
boot config choice primary config-file <Filenametosave>
Any point that you want to save config use:
save config file <SameFilename>
Once you boot the device once, and verify it automatically loaded the correct config it looks like you can use write mem, or save config and it works like normal.