Hello @hingarthu, do a search in your Steam library for Proton Voice Files and test if installing that is what you're looking for.
Hi kisak-valve - Proton Voices is indeed installed. I've wiped and reinstalled it several times, each time when I chose a new Proton version.
Elite Dangerous Exploration Buddy also spits out its own log:
Steps to reproduce:
Install Proton Voices.
Run Exploration Buddy to create the prefix. Exit Exploration Buddy.
Use Protontricks to install .NET 8.0 and Microsoft Speech (sapi) in Exploration Buddy's prefix.
Run Exploration Buddy.
Click on menu/hamburger:
Select Preferences:
Select the Speech tab:
Take note the Voices dropdown contains a collection of voices. Select a voice from the dropdown and press the Test Speech Output button. Note that nothing happens.
I was able to get the text-to-speech feature to work.
I suspected that this was a Proton Voice File path issue. I delved into the protontts source code, and saw a reference to an environment variable named "PROTON_VOICE_FILES". A quick environment variable check via the Wine command shell in Protontricks showed that there was no environment variable with this name. As a quick remedy I added the launch parameter PROTON_VOICE_FILES="[path to Proton Voice Files]" and the text-to-speech feature now functions.
This is a workaround. If the Proton Voice Files installation were to be moved to another location (e.g. disk/path/etc) then this feature would fail.
Given that Proton Voice Files tool is installed via Steam, it would seem that the path/location to Proton Voice Files is not being recognized by a given Steam Compatibility Tool/Proton version.
I was able to get this feature to work using multiple Proton versions, but settled on Proton 11 (beta).
ge-proton10-34x1 2026-05proton 10.04x1 2026-05proton experimentalx1 2026-05PROTON_VOICE_FILESx1 2026-05PROTON_VOICE_FILES="[path to Proton Voice Files]"x1 2026-05protontts.dllx1 2026-05
Compatibility Report
System Information
I confirm:
steam-12353214146861334528.log
Symptoms
I've been running a non-Steam third party add-on for "Elite Dangerous" called "ED Exploration Buddy" for quite some time, originally using Proton Experimental. There is a text-to-speech component with this add-on, and it's been working fine until recently (April 26, 2026 or thereabouts). I had been able to get this feature to work by installing .NET 8.0 and Sapi using Protontricks.
The Text-to-Speech feature no longer works. I've tried running this add-on with other Proton versions, deleting all data and applications via Protontricks before swapping in a new version.
The issue seems to be related to missing Proton Voice files in that protontts.dll cannot seem to find them - this is denoted in the steam log. Proton Voices appear to be registered in the prefix's registry, and the voice options are available in ED Exploration Buddy, but the text to speech feature does not work.
Reproduction