D5 Lite for Revit fails to launch: SessionGuard cannot write guard.ready when Windows username contains non-ASCII characters

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1

D5 Render Version: D5 Lite for Revit (Beta) v1.1.0.0001 / D5 Launcher 1.2.0.0120
Graphics Card: NVIDIA GeForce RTX 4070 Laptop GPU
Driver Version: 32.0.16.1088
Host Software: Revit 2025 and Revit 2027.2 (fails identically in both)
D5Lite_Bug.zip (35.3 KB)

Issue Description:
Screenshots/Videos Description: Clicking “Connect to D5 Lite” in Revit does nothing visible. The tooltip changes to “D5 Lite is running”, but no window ever appears. I checked all monitors, Alt+Tab, the taskbar and Task Manager, and there is no D5 Lite window anywhere. D5 Render and D5 Sync work perfectly on the same machine.

I searched the forum before posting and could not find this specific issue reported.

Root cause (from logs):

The engine process launches correctly from C:/ProgramData/D5 Lite Revit/Engine/D5Lite.exe, but D5LiteDump.exe (SessionGuard) fails to write its guard.ready file:

Log.ERROR: Json write error: failed to open file
In skr::JsonWriteResult::dump_error At …/SkrCore/json.hpp:641
Log.ERROR: [SessionGuard] event=session_file_publish phase=temp_write status=failed
kind=guard_ready
path=C:/Users/RafaMoscardóERRE/AppData/Roaming/d5lite/revit/dumps/sessions/…/guard.tmp
In write_json_atomically At …/d5_lite_dump/src/session_guard.cpp:326

The guard then exits with code 4, and Revit reports:

Log.ERROR: [SessionGuard] event=startup phase=ready_wait status=child_exited exit_code=4
Log.ERROR: [LiteInterfaceRuntime] [SessionGuard] strong ready barrier failed
Log.ERROR: [LiteHostLifecycle] event=start phase=app_session status=failed
Log.ERROR: failed to open editor through RPC: 0

Evidence this is a character-encoding bug, not a permissions issue:

  1. The target directory exists and I can manually create files in it, so it is not a permissions or antivirus issue.
  2. The D5 installer log shows the same path corrupted as “RafaMoscard?ERRE”, confirming the encoding is mishandled somewhere in the D5 codebase.
  3. My C:\Users\ folder contains a stray directory named “RafaMoscardóERRE”, created by a different application with the same class of bug (UTF-8 read as Latin-1). Screenshot attached. This is a known failure pattern for non-ASCII paths.

Why the installer workaround does not help:

Installing as “All Users” (engine correctly placed in C:/ProgramData/) does not fix it, because the session/dump directory is always under the user profile and is not configurable.

Steps to Reproduce (optional):

  1. Use a Windows account whose username contains a non-ASCII character (e.g. “ó”).
  2. Install D5 Lite for Revit.
  3. Open Revit and click “Connect to D5 Lite”.
  4. The tooltip shows “D5 Lite is running” but no window ever appears.

Request: Please make D5LiteDump.exe handle non-ASCII characters in user profile paths (wide-character / UTF-8 aware file APIs). This will affect any user whose Windows account name contains accented characters, which is very common in Spanish, French, Portuguese and other locales.

2

Hi @rmoscardo

Just to clarify, does changing your Windows user account to one without non-ASCII characters resolve the issue?

3

Hi,

Not yet. My Windows account name is managed by our IT department, so I can’t
change it myself. They’re working on it and I’ll confirm here once it’s done.

Meanwhile, I’ve attached the full log package generated via Help > Collect Log
Files as you suggested.

One additional finding that may be useful: the workaround suggested in this
thread (installing outside the user path) does NOT work for D5 Lite for Revit:

I installed with “All Users”, so the engine is correctly located in
C:/ProgramData/D5 Lite Revit/Engine, but the failure persists. The SessionGuard
writes to a fixed, non-configurable path under the user profile:

C:/Users/RafaMoscardóERRE/AppData/Roaming/d5lite/revit/dumps/sessions/

The D5 Launcher shows the same problem in its own log:

[launcher] [error] Failed to write key ‘HardwareId’ to settings file
‘C:/Users/RafaMoscardóERRE/AppData/Roaming/D5Launcher/config.ini’

Thanks for looking into this.

zziplog.zip (121.8 KB)

4

Hi @rmoscardo

Thanks for this, we’ll look into your logs and see what we can do improve this issue.

1 Like
5

Dear D5 Support Team,

I am currently experiencing an issue with D5 Lite for SketchUp v1.6.0 .

My environment is:

  • SketchUp 2026
  • D5 Lite for SketchUp v1.6.0
  • Windows 11
  • NVIDIA RTX 4090
  • D5 Render itself works normally

The problem is that D5 Lite does not launch from SketchUp.

The log shows errors such as:

[SessionGuard] strong ready barrier failed

app_session status=failed

failed to open editor through RPC: 0

I tested the same installation using a newly created Windows user account with an English-only username, and D5 Lite appears to launch normally under that account .

However, my main Windows user profile uses a Korean username, so the user folder path contains Korean characters:

C:\Users\황진웅

Therefore, I suspect that D5 Lite v1.6.0 may have an issue handling non-ASCII / Korean characters in the Windows user profile path.

I would prefer not to create or migrate to a new Windows user account just to use D5 Lite.

Could you please provide me with an offline installer or download link for an earlier version of D5 Lite for SketchUp, preferably v1.5.0 ?

I would like to test whether v1.5.0 works correctly with my existing Korean Windows user profile.

If v1.5.0 is unavailable, any previous stable version compatible with SketchUp 2026 would also be appreciated.

Thank you for your assistance.

Best regards

6

Thanks a lot!

7

Hi @dwct7366

Can you send us your log files? Please send is to me privately here in forum.

Log1
Log11276×766 55.8 KB

Log2
Log21278×766 51.4 KB

8

Hi @dwct7366 @rmoscardo

We’ve fixed the issue with a newer build; we’re set to officially release this version next month. Thank you. :saluting_face:

1 Like
9

Hi @Clov,

Thanks, glad to hear it’s fixed for the next release.

Confirming the Unicode fix works: the SessionGuard now completes successfully
(ready_publish status=completed, ready_exists=true) in every session, with my
Windows username unchanged. That issue is resolved.

However, I’m hitting a different issue with this build. The D5 Lite window opens
but stays on “Initializing, please wait…” indefinitely. I’ve reproduced it in
three sessions now:

  • 26/08 14:07: the engine eventually initialized after a 21-minute gap with no log
    output, but the UI never left the loading screen. Left running overnight, no change.
  • 27/08 08:19: over one hour, exited with engine_initialized=false. The engine never
    initialized at all.
  • 27/08 09:24: same behaviour.

The same error appears at startup in all three sessions:

Log.ERROR: Error opening file: C:/ProgramData/D5 Lite Revit/Engine/./…/bundles/dxil-shaders.bundle (error code: 3)
Log.ERROR: [Bundle] failed to open bundle: dxil-shaders.bundle

Error code 3 is ERROR_PATH_NOT_FOUND. I checked the filesystem and there is no
“bundles” folder anywhere. C:\ProgramData\D5 Lite Revit\ contains only Engine,
resources and Uninstall, and there is no bundles folder inside Engine either.

Since the log resolves the path as Engine/./…/bundles/ (one level above Engine),
this could be either an installer packaging issue or a path resolution issue in
the code.

Installed via “Install for all users”, running as administrator, on Revit 2027.2.

Full log package attached, collected via Help > Collect Log Files. The relevant
files are D5Lite_2026-08-27-08-19-11.0.log and D5Lite_2026-08-27-09-24-59.0.log.
zziplog.zip (261.8 KB)

10

Hi @rmoscardo

Just to clarify, this issue that you have just reported can be consistently replicated in all files, regardless of their size, correct?