Looking at the Image Rendition error messages ...
convert.exe: unable to open image `
D:\Temp\=GUID-4D3EF06B-5EAE-472B-BBC0-204739D1B9C6=2=en-US=Print.png': No such file or directory @ error/blob.c/OpenBlob/2695.
...
Restarting IIS has the knock on action of reconnecting to the database, which can help when facing issues interfacing with the database (i.e. timeouts, dropped connection due to network outages, locks etc). The above error indicates there was an issue retrieving the source image GUID-4D3EF06B-5EAE-472B-BBC0-204739D1B9C6=2=en-US=Print.png from the database, so it can be saved to the server's file system, in order for it to then be processed by the convert.exe binary to generate the online and thumbnail image resolutions of the image. After which, when this is successful, the generated resolutions are then imported into the database.