Are you trying to acquire the massively popular Slay the Spire 2, attempting to buy something else on Steam, and just come across this cryptic error message?
You’re not alone, because this happens often when a popular game launches on Steam. Having prior knowledge, here’s what we know about how to fix the problem.
What is Steam error E502 L3?
Error E502 L3 points to a server-side issue, meaning it’s a problem on Valve’s end. To be more precise, this specific error code can pop up whenever you’re logging in or browsing the Steam store. It also commonly refers to a problem in Steam’s storefront, one likely related to the massive potential customer influx that hits the platform whenever Valve announces a hot new item.

The latest Steam Deck was one such item when it came out, as it immediately jumped to the top of Steam’s wishlist charts upon its announcement. It happened again with Hollow Knight: Silksong in September 2025, and now it’s happening with Slay the Spire 2, which has been one of the most anticipated and wishlisted sequels on the platform. Another hot game, Marathon, was released at the same time on the same day, so the servers are likely getting walloped.
As such, unless the problem has already been fixed and you’ll just have to restart Steam for it to regain access to your transactions, there’s nothing you can do other than wait and check SteamDB for updates on all sorts of server-side issues.

Valve was quick to acknowledge the issue the last time it got so widespread with a game like Hollow Knight: Silksong, so it’ll likely be quick to get to it this time around as well.
Just sit tight and wait for issues to subside so you can purchase Slay the Spire 2. The issue should subside in due time.