Products disappear

I'm having a problem where my products are disappearing after saving. They're still in the database. They still show up in the Admin panel under Products with the appropriate categories linked. They just don't show up in the categories page. It's happened with two products so far. If I manually type in the path (such as mysite.com/category/this-product) it says Product Not Found!

Does anyone have this problem??

Looks like a possible problem with you SEO URLs

Please give us a link to check

The product doesn't show up even w/o any SEO urls. It's still in the mysql database. Still gets loaded into the Admin > Catalog > Products section. The product is now being linked to ALL categories. However the product still isn't being displayed by the controller or the template. Creating a new product in the same category will show the new product properly.

I've tried copying the disappeared product, and enabling the new copied one. But the new one still doesn't show up. *Of course all products are enabled not disabled.*

I can't provide any links because nothing shows up. All you get is the php for product not found. The product id is 53. But category?product=53 w/o seo urls also shows not found.

Maybe somehow despite being "Enabled" the product is still "Disabled".

I'm actually not the one who caused this to happen. Another person was editing in the products and he encountered this problem twice in past day so I don't know how he did it.

One thing I can think it may be is that the product is not assigned to a store in the links tab

Normally this is ticked by default for single stores, but if for some reason it isn't ticked, then it could be what is causing the problem.

Today I met the same problem and the answer is just above me, thank uksitebuilder!
The problem occurs when we edit product_form that affect the SEO or Store fields .