Then we have to check many things:
- we have to make sure the new template you installed does not overwrite any core files, which will also cause the default template to fail as well.
For example, in the template package you installed, do they have any file like new_products.php under includes/modules/
- We also have to check if you installed any other module that may cause the problem as well. Do you have a list of modules you installed?
I no longer provide installation support on forum for all my modules. However, if there are real bugs with the modules please feel free to contact me