dll. files (Dynamic Link Library files) are what the program uses to link various processes together. When they go missing the processes you try to add can't be loaded for use. Sometimes these will show as the program loads and initialises.
They either come with the editing package, supplied effects, or are a part of the operating system.
If one or more are missing we need to see which ones they are to give you any idea as to what may need to be reloaded. If they are a part of Windows you may be missing an instillation package or driver.
If you can take screen shots of the warning messages and post them here using the the upload image tool above your posts when you reply, I have outlined in this image
take screen shots of the warning messages and post them here using the the upload image tool above your posts when you reply
It is going to be very difficult for fellow-users to advise you without that information!
Also, which version and build of Windows do you have? If you're not sure simply press the Windows key + R and on the screen that opens, type winver. Tell us what is shown there.