Roon client won't start correctly after Windows 11 update

Roon Core Machine


Roon Core is running on an old MacBook Air. I

Networking Gear & Setup Details

DAC is connected by wire to Netgear ORBI satellite.

Connected Audio Devices

Roon, on MacBook Air, communicates wirelessly with PS Audio Jr DAC

Number of Tracks in Library

200 CDS, plus Tidal

Description of Issue

The Roon Client running on brand new Dell laptop (XPS 17 9720), running Windows 11, suddenly will not start correctly. The error message is: “The application was unable to start correctly (0xc0000135). Click OK to close the application.”


Windows 11 was recently updated, via these updates:
KB5013943 cumulative OS update
KB5013628 (.NET framework)
KB5014329 (.NET security)


Hi @Christopher_deRham ,

Has that guide helped resolve the issue on your end? Let us know!

Initially, no. That notice simply informed me that the problem was caused by an incompatibility between Roon and Windows 11, and that the problem pertained to .NET Framework 3.5.
The graphic included in “the guide” was too small to read clearly, and clicking on the link generates a webpage that makes no mention of the check box issue.

That said, I subsequently figured out how to get Roon working with Windows 11 again.
After installing the most recent Windows 11 update (not including any optional updates), I found that if I went to: Systems / Apps / Optional features / More Windows features, I would find a checkbox that would activate the needed .NET Framework 3.5 component of Windows 11.
I simply checked the box for .NET Framework 3.5 and allowed the installation of the missing software. After a restart, I found that Roon would work normally again.

It would have been better if “the guide” that you provided had included explicit instructions as to how to get to the check box in question.

BTW, this procedure frees up Norton Utilities to work as well…

All included in the linked guide:

It was a pleasure to help you. Plonk.


[Moderated] The link instead suggests Command Prompt instructions to reinstall the .NET framework, or to UNINSTALL the most recent Windows 11 update. [Moderated]

The link produces for me the following alternative option to repair the .NET framework 3.5:

Did you read this? Did you look at the screenshot? @BlackJack’s link provided all the information necessary to solve your problem. Some courtesy of acknowledgement would have gone a long way.

1 Like

I hope you realise that a fellow human being, a user of this forum, is voluntarily trying to help here, and provides useful information? Maybe you want to reflect and give consideration to following up in an appropriate manner. Kindness is a valuable thing.