Unable to start a debug session in visual studio 2026

ClaudiaPautz

Hi,

I am using visual studio community 2026 vs 18.0.2, and PHP Tools for Visual Studio Version: 1.88.18138.2026 Release Date: november 25 of 2025.

The Error shown is:

Unable to Start Debugging on the Web Server. Unable to start debugging. Legacy script debugging (Internet Explorer, cscript, etc.) is no longer supported in this version of Visual Studio. The PHP Tools for Visual Studio failed to attach to the Web Server. Please contact vendor for assistance.

JakubMisek

ClaudiaPautz, thank you for reporting that.

For now, as a workaround, try disabling "Script Debugging" in the Debug Run toolbar.

ClaudiaPautz

I forgot to say that the same project configuration works flawless in visual studio community 2022.
Thanks in advance for any suggestions.

ClaudiaPautz

Thanks for the suggestion, but the script debugging option is already disabled.

MiloslavBeno

May I ask what browser is selected in the Debug Run toolbar?

So far, we haven't been able to reproduce this on VS 2026 Insiders edition. We will try on general release and get back to you.

ClaudiaPautz

I apologize for the delay.
The browser is Google Chrome.

MiloslavBeno

Hi,

Thank you. May I also ask to check what project type is ds2018? We do not currently support Dev Tunnels on PHP Web Projects, so they shouldn't be visible in the Debug Run Panel :-/

ClaudiaPautz

ds2018 is a php 8.1 project, no tunnels...as I told, this exact project works flawless in visual studio community 2022. The debug in vs 2022 works just fine.
below is a screen shot of the project properties: