In some cases, steamui.dll errors could indicate a registry problem, a virus or malware issue, or even a hardware failure.
Steamui.dll Errors
There are several ways this error might show up on your computer, such as:
Steamui.dll Not FoundThis application failed to start because steamui.dll was not found. Re-installing the application may fix this problem.Cannot find [PATH]\steamui.dllFailed to load steamui.dllThe file steamui.dll is missing.Cannot start [APPLICATION]. A required component is missing: steamui.dll. Please install [APPLICATION] again.
A steamui.dll error might appear when Windows starts, when a program is opened, when a program is running, when a program is closed, or at nearly any time during a session of Windows.
How to Fix Steamui.dll Errors
Follow these steps in the order they’re listed below to try the more likely fixes first. If you suspect this, but you’ve already emptied the Recycle Bin, you may be able to recover the file with a free file recovery program. If either of these DLL files is actually still present at the root of Steam’s installation directory (which is normally C:\Program Files (x86)\Steam) and haven’t been deleted, try deleting the steamui.dll or libswscale-3.dll file. Then, open Steam to force it to update the program and replace the DLL file with a fresh one. If that doesn’t work or if you’re using a beta version of Steam, the quickest way to resolve the DLL error may be to remove the C:\Program Files (x86)\Steam\package\beta folder. It’s even possible that the error you’re seeing is related to a hostile program that’s masquerading as the file. If the hardware fails any of your tests, replace the memory or replace the hard drive.