Pokemon GO’s ‘invisible obstacle’ is actually Kecleon, the color-changing chameleon Pokemon. It has changed color to match the PokeStop behind it, which prevents you from spinning the PokeStop.
Luckily, it is possible to remove Kecleon from the PokeStop so you can spin it and get your items. Doing this also makes it possible to catch Kecleon!
Here’s how to catch Kecleon in Pokemon GO so you can remove it from the PokeStop and add this color-changing Pokemon to your Pokedex!

How to Move the Invisible Obstacle
To move the invisible obstacle, you first need to know how to spot Kecleon in Pokemon GO. Then, once you’ve identified where it is, press on Kecleon repeatedly until it jumps off the PokeStop.
After Kecleon (the ‘invisible obstacle’) has hopped off, you can spin the PokeStop.
Additionally, after Kecleon has jumped off of the PokeStop, it will appear on the overworld map. This lets you then press on and catch Kecleon!
But can you catch a shiny Kecleon in Pokemon GO?

Now that you have moved the invisible obstacle and caught Kecleon, you might also want to find out how to catch other elusive Pokemon in Pokemon GO: