You can't natively do this (yourself), but contact Zapier support (support@zapier.com) and they might be able to. In the future, I recommend making a copy of a Zap (while here: https://zapier.com/app/zaps click the down arrow on the Zap and then 'Copy'), before doing anything iffy.

However, simply testing steps should not break your Zap. If you post more info (maybe screenshots of the errors or a loom video) we may be able to help. Of course Zapier Support can help with that too if you are already about to message them :)

To add to the great advice from @BlakeBailey, the Support Team don't have a way of restoring Zaps to a previous version, sorry about that!

However, @BlakeBailey is right that just testing the Zap (without making any changes) shouldn't have broken it. Could you tell us a little more about the issue? Is it that the test isn't working and so you can't turn it on? One thing you could try would be to skip the test for the step(s) that's causing an issue and turn the Zap on and then keep an eye on it to make sure that it's working properly.

If you've tried that and something is definitely broken then if you could let us know what the Zap is/error says, that would be super helpful

@Danvers ah got it, thanks for letting me know! I never know what mystical powers support does or doesn't have, though I did suspect that this wasn't one of them.

Either way, @Josh_F do let us know what was going on (or if you resolved it), and we can chime in :)

My developer resolved it. Thanks so much guys. I will make a copy next time before doing any testing. You guys are great.