Resolving conflicts between modules...

[Terry]

In PrestaShop, many features and most modules and addons use a core PrestaShop system called 'hooks'. Hooks, among other things, can be thought of as a holder and/or processor for modules.

There are times when adding a new module to PrestaShop can cause issues because another already installed module is making use of the same hooks required by the new module.

For example, you may decide to install the Agile Multiple Seller module, but you have already installed a 3rd party email verification module. This module has already taken control of the hook needed by Multiple Seller for this particular purpose, and may not allow Multiple Seller to perform correctly.

One option, of course, is to remove the email verification module. However, another possible option might be to adjust the load position, or hook position, so that the Multiple Seller module gains control of the hook first. In many cases, this may resolve the issue.

If you're not familiar with, or comfortable with adjusting the hook positions, a simpler alternative may be to simply uninstall both modules, then reinstall the Multiple Seller module first.

Though this process is not always guaranteed to work, in many case it is a simple way to resolve this type of conflict.