Perhaps save with different name at each save, even if that is just putting a number at the end of the name. That way you can return to the previous zoo or post both for someone to check.
What zoo map were you using? There are some map updates over at DG for some of the original maps.
Eventually I will do a fence hack on all the my user made fences that are not in the Tek SuperHack. That would be all the Tall walls and also all the coloured dino walls and a few others that I have done.
If you read the additional info at DD you should avoid files the contain "Error"
Unfortunately I have not done most of Hawkkeye's animals yet. A word of advice if you are downloading from his google drive. His ztds do not contain his initials so that would cause a .ztd name conflict in some cases. The dhole was one where ZA also have or had dhole.ztd. Also if he had zipped them you would be able to test the file to make sure it downloaded correctly and was not corrupted and the ztd date would remain the same.
There are a few of Borsato's files that have an internal id conflict with the animal he used as a base. I am working on a list of those.