I'm running into an issue where the SuperContainer Companion plugin seems to no longer work on a specific image.  The image preview displays fine but no plugin functions seem to do anything (and no errors reported by the plugin).  When I investigated on the server and tried to delete the problematic image from the SuperContainer directory, Windows displayed an error message saying that the file was in use by java.exe and could not be deleted.  To resolve the issue I have to kill Java processes on the server and restart the server to get SuperContainer working again.  This has happened twice in the past week and according to users, they hadn't manipulated the file in any way since the previous time the issue occurred.  It was only downloaded via Custom Web Publishing (PHP).

Any idea why this might happen?  Setup is FileMaker Server 16.  Windows Server 2012 R2 operating system.   The file size for this particular image is 77MB, in case that is relevant.

That is a pretty large image file. This only happens with one image? What image type is it? Do images of the same type result in the same issue? what about a different image type but similar size?

Only happens with the one image.  It is a JPEG.  So far no reports of issues with other images.  I think it's pretty rare for the images to be this size so I'm not sure that there's been a comparable test performed.  I'll consider trying various tests if this continues to occur.  One interesting thing I noticed is that after ending Java processes and removing the image file on the server, the file's name and other info still appeared in the SuperContainer web viewer in their database (even after refreshing the web viewer) until I uploaded another file.

I suspect this is more of a fluke issue, like maybe an interrupted upload of the image, rather than an ongoing problem but I wanted to see if there was a known reason why this might happen so I could prevent it from becoming a larger issue.