OpenCart version: 126.96.36.199
As with a few other users I have quite a lot of products on my site (close to 20000). This greatly slows down my Admin -> products when first loading.
I had a similar problem on the front end, where the search engine was taking too long to respond. After running an index this cut the time from 60 seconds to 2 seconds.
Is there a way to Index the Admin side of things?