"Open Transport is incompatible with all Assistant Toolbox versions prior to version 1.3. If you are using Mac OS 7.5.x and AppleTalk is off every time you restart your computer, check the version of Assistant Toolbox installed in your Extensions folder. You can install Assistant Toolbox v1.3 using the System 7.5 Update 2.0 Custom Install option.
If you are using Mac OS 7.6 or later, Assistant Toolbox is built into Mac OS 7.6, so you do not have to check the version. However, if you have a version of Assistant Toolbox installed with Mac OS 7.6, throw it away."