There could be many causes to this problem, but the most often encountered are:
The application is corrupted, meaning that it has a bug in its code that prevents it from finishing the job.
You are using unsupported content in the application and because of that it causes a crash of internal modules.
The files used by the application might be locked. Reboot the PC to fix this issue and run it as Administrator.
A multi-format photo-processing tool to convert pictures to various formats.
Change the size and apply various effects to batches of pictures.
Image Converter Plus for converting images to different picture file formats.
There could be many causes to this problem, but the most often encountered are:
The application is corrupted, meaning that it has a bug in its code that prevents it from finishing the job.
You are using unsupported content in the application and because of that it causes a crash of internal modules.
The files used by the application might be locked. Reboot the PC to fix this issue and run it as Administrator.