[Wintermute0110]

What version of AEL are you using? Yeah, if you have further problems please put the full debug log (enable debug in AEL but not in Kodi to not clutter the log).

Scrapers (except the offline metadata) are not working at the moment in AEL 0.9.7 so it's a good idea to disable them in the addon settings for the scanner. Anyway, the crash you are getting should not happen (it's a bug). In AEL settings, ROM scraping tab, set "Metadata scraper" and "MAME metadata scraper" to "Offline scraper". 

Many thanks for your reply and help. I'm using AEL 0.9.8 - I realised yesterday that I haven't updated to Leia 18.2 (still on 18.1) is it worth doing that to see if that makes a difference?

Full debug log here onozajiqew.kodi (paste) - I assume it's the same Kodi log file just with debug turned on in AEL and not in Kodi, rather than a separate log file.

Both of those scrapers were already set to "offline scraper"

Many thanks

OK. Please install AEL from this commit. Recently I did some work on AEL trying to revive the scrapers with some code from master branch made by Chrisism, however it is still far from finished. Next couple of weeks I will be on holidays so expect no support. The commit I gave you is the current most stable version of AEL.