BACKUP all files first.....

As you are using a template and hopefully using the override system...

First switch to the classic template and see if they are there for the purpose of determining is you have edited files that are in your template overrides folders or core Zen Cart files.

If they are your template files comnpare these to default copies.

If classic also does not show the links then reload all Zen Cart files form the same version disribution

One of the above will correct this