A bug that I have found

Was it a specific pokemon or type of pokeball? I just attempted this but had no issues.

Basically all the pokemon, and pokeballs, greatballs though I haven't used any other types of pokeballs yet.

How about a specific area? I had no problems using pokeballs or greatballs

All the areas up to the second gym.

Well I am thoroughly confused. I am perfectly capable of using pokeballs on all pokemon. Sorry that I couldn't be of much help.

That's ok.

This is a known bug that's listed in the thread at the top of the forum. Most likely you used F12 to soft reset, which currently causes the bug that you're experiencing. When you want to reset and plan on catching Pokemon after, just close out of the game entirely for now. It's a little tedious but it prevents the bug from occurring.

Yep, unfortunately I can't reproduce this bug (like Bocajian) under any circumstances, so it's really hard to fix it. If anyone knows exactly what causes it, please tell me (as soft resetting doesn't cause any problems for me)

Well that explains a lot...