I tried installing an add on to my magento site, and now I cannot see/access any tabs when I login.
I have logged in with another code that we use for our suppliers to access and they still have the tabs available to them.
Can anyone help?
Welcome to Magento Forum!
I want to know what's your add on(extension) you have just installed to your site? You should check: this extension supports for your current Magento version? There is a quick solution for you: go to <Magento_Root>/app/etc/modules/ => find registration xml of this extension. Then, change the active tab to false. Clear cache and refresh your page again.
That's weird. I supposed that you're Admin. So it's weird when Admin doesn't have full rights but Suppliers do.
If you're not Admin then ask the Admin to check User_Role for you.
You should reset admin role: