Fail to add the products and automatically resending to the admin page

[Indieway]

Hello,
When I'm trying to add new product in VirtueMart 3.0.18, after saving all product's details, I'm automatically resending to the start page(admin page where I need to put password and login) So fail to add the product. What is the reason for this?
Can you, please, assist me on that one?
Thank you!

[mcmannehan2002]

Check your session lifetime.
System -> Clobal Configuration -> System -> Session Settings