How do I get effects to loop without cutting out abruptly at the end?

The loop count value should be a whole number (1,2,3, etc), not 2.5 for example. If you set Loop Count to 5 for example, it’ll loop 5 times no matter the slide length (e.g. 10s slide / 5 => 2s per loop, 60s / 5 =>12s per loop).

See the following tutorial for additional information about this process: