Some hacks conflict with ZT when used at the same time. what you are experiencing could be a result of using the 2 hacks together.
Here is something for you to try. Remove both of the hacks and start up your game to be sure it runs properly then install one of the hacks and observe the tri to see if the invisability problem is there. Then remove that hack and install the other and check the tri again. Then install both hacks again and check the tri again. If you have the invisability problem with only one hack installed then let us know which ons so we can look into why it is happening.