This is where Steam stores temporary download files, but it can sometimes cause problems with the gaming client.
Here’s how (and when) to clear it.
When Should You flush the Steam Download Cache?
Clearing the cache can also help resolve errors users encounter when downloading or running games, such aserror 16.
What Happens When You reset the Steam Download Cache?
When you flush the download cache, Steam logs you out of your account and cancels your pending downloads.
The download queue is cleared and any mods you have installed are also removed.
Likewise, let any pending downloads complete before you erase the cache.