To recover old WhatsApp conversations and photos is very simple, as long as you have a backup or have synchronized your WhatsApp account with Google Drive. In case you do not have any backup or account synchronized with Google you will not be able to recover the conversations.
How to recover WhatsApp conversations and photos
First of all we have to uninstall the WhatsApp application from our phone and install it again. After accepting the conditions of use of WhatsApp and verify the phone number will appear a window asking for RESET, it is important not to skip this step, otherwise all conversations will appear blank. After selecting that you want to restore all conversations will begin to download, when you finish restoring the conversations will begin to download all the photos and videos you had in the conversations.
It is important to follow all the steps, from having a backup done (HERE you will find how to make a backup), to uninstall and reinstall the application.