Client does not load, only taskbar small box appears with blank square

Question

This is for the client named Ultima Online, this occurs often, I select launch client, then windows does not load the client program, only a small box appears in the taskbar.

Then I have to delete the folder UORenaissance located in c:\UORenaissance, then reinstall, then windows loads the client, when I close the client, then attempt to reload it again through the client launcher (always used) at random, it does not appear.

This is picture of how it looks when it fails to load the client in windows, only appearing in the taskbar

I used this laptop for two years with this client and this did not occur.

Microsoft DirectX info

runtime version 12.00

hardware supported version 11.1

Laptop is latitude e7450, 16gb ram, 512gb ssd

This error while two other clients were loaded in windows, the third was operational and open, I closed the third client, attempted to reopen through launcher, only a white blank box appeared in the taskbar, the other two clients were operational.

Answer 1

Hi Stechnical10600

Thanks for posting in the Microsoft Q&A Forum!

I understand how frustrating it is when a client that has worked for years suddenly refuses to open properly. Based on your symptoms and on what other ClassicUO and UO:Renaissance users have encountered.

This happens most often when running multiple clients, when Razor’s CPU settings interfere, or when Windows assigns the client to Intel HD 5500 in a mode that fails to create a visible window. This exact behavior has been reported by other players. In one verified case, forcing ClassicUO to run using the GPU instead of the Intel onboard graphics fully resolved the invisible‑window issue.

Below is some fixes that consistently resolve the problem for users with the same symptoms. Since Windows 10 is EOS since 2025, you can still try these:

Force ClassicUO and Razor to use High‑Performance GPU

• Windows Settings > System > Display > Graphics Settings
• Add ClassicUO.exe and Razor.exe, then set both to High Performance.

Disable Razor’s Smart CPU Usage Reduction

• This option causes whitescreens, crashes, and blank client windows when re‑launching.

Add antivirus exclusions

• Excluding your UO, ClassicUO, and Razor folders prevents silent blocking that leads to failed window initialization.

Update or roll back your Intel HD 5500 drivers

• Some Intel HD 5500 driver versions are known to fail during initialization of DirectX components. A verified stable version is 20.19.15.5171.

Reinstall ClassicUO to restore any damaged zlib or resource files

• There are cases where missing or damaged zlib files prevented proper loading.

Avoid minimizing multiple ClassicUO instances

• Running several clients at once is known to trigger context loss, UI failures, and slowdowns.

Hope these can help. Feel free to update here if there's any progress!

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