ppt source code：
src.zip (3.3 KB)
origin ppt files:
测试插入对象 (1).pptx.zip (33.6 KB)
converted error:
image.png (145.5 KB)
The words changed to random code,please have a check.
Can you please share the use sample code and also try using latest Aspose.Slides for .NET 20.12 if you are using some older version. Can you please also ensure that font used in your presentation are actually available on machine where you are performing rendering.