Thank you for confirming the savegames files were not corrupt as expected. I had noticed the issue with permissions and ruled that out earlier, but I repeated the removal of the readonly flags just in case. After turning off my antivirus protection, and invoking as admin with no effect, I tried deleting just the 0.png file. This time the sharing violation disappeared in the output_log.txt file but the Continue and Load buttons were still greyed out. I also noticed that the 0.png file was still deleted. I tried a number of games with what files got deleted but still got the non-working Continue and Next buttons although the shared violation stayed removed from the output-log.txt file. At this point I started to lose track of what I had done and which actions were recreating the various temp files and which were not. I decided to do a restart from scratch by deleting all of the savedgames and starting a new one. This time when I saved the new game, I reloaded it immediately. I then exited, but not all the way. I reloaded from the New-Continue-Load screen, and then finally exited completely. On each of the loads I rechecked the output_log.txt file to ensure the shared violation message was still missing. Wonders - The next invocation gave me working Continue and Load buttons. I now went back to my savedgames backup (which I had created at the very beginning of this exercise) and restored my oldest save - it worked. I'm back in business at lvl 12. Here's what I'll try if this happens to me again. I'll make a backup of all savedgames file. I'll read the output_log.txt file now that I know what messages to ignore (I've enclosed the new one where everything appears to be working.) I'll create a new game, save it, load it, exit to the New-Continue-Load menu and Load. The I'll exit completely to see if the problem is resolved. With the problem now gone, it's hard to know exactly what the magic was, but I'm just be happy to be back in the saddle.
Thanks
output_log.txt