Multithreading in Aspose.Slides
While parallel work with presentations is possible (besides parsing/loading/cloning) and everything goes well (most times), there is a small chance you might get incorrect results when you use the library in multiple threads.
We strongly recommend that you do not use a single Presentation instance in a multi-threading environment because it might result in unpredictable errors or failures that are not easily detected.
It is not safe to load, save, and/or clone an instance of a Presentation class in multiple threads. Such operations are not supported. If you need to perform such tasks, you have to parallel the operations using several single-threaded processes—and each of these processes should use its own presentation instance.