Piece of bad software development: D5

I never had such a big problems like with D5.
I use huge amount of software for rendering and post processing but with D5 I have always problems.
For no reason, suddenly , D5 stopped working giving me DLL error. I can open D5 main Window Only but nothing works there.
To be clear: I have top PC hardware, clean system, checked forum with D5 issues, reinstalled D5, drivers, etc…

Any idea whats is wrong?

Hi Januz

I have been working in architectural and 3D design for 30 years, from 3D studio 2 (the first ones, later called Max) Maya, Revit, Vue and Lumion (from V7 to V12), always with official versions.

Since D5 1.2 came out I have been working with two official perpetual licenses (I was lucky enough to take advantage of that offer) so I can say the following from my experience.

I only had D5 crash once, when putting grass in a texture that covered the entire scene. Now I always limit the past to necessary sectors.

I only had the Dll error problem once, when upgrading to version 2.4, and curiously, on one of my workstations, this problem was solved, never again.

I think that the problem of instability with D5 is that since it is free, its use is very extensive among a large number of people with different configurations. This, added to the fact that the software is very demanding on resources, not all of them achieve the necessary configuration for demanding jobs.

To this I add that D5 constantly makes very extensive updates that other software does not even match its annual versions.

For all this, it is logical that users are pushing D5 to its stability limits, but it is worth accompanying them in this progress.

I’ll give you my link about my solution to the Dll problem, I hope you find a solution.


"I had this problem for 3 months but I solved it as I describe in the post that I transcribe here,

I have two Workstations with two Pro licenses in each one, both with the same system and configuration, but when updating to version 2.4 in one of them the Dll error problem appeared.

It seems that when D5 is loaded or updated, this file is deleted by the antivirus or the firewall, or I don’t know what, but not always.

For more than 2 months I tried all the solutions on the forum except the remote intervention of my PC by the D5 support team.

I solved it by replacing the incorrectly loaded Dll manually in Windows System 32.

There are several solutions on the internet on how to do it, many of them did not let me replace the file because the permissions did not allow it even though I had allowed them.

In order not to harm the equipment, my IT consultant did it to configure the system for me, and he could only do it by renaming the Dll file with a different name, then the permissions worked.

This is the forum link for this problem, there is a solution out there that works better for you than it does for me.

https://forum.d5render.com/t/got-notification-of-launch-failure-might-be-caused-by-system-dlls-missing-try-to-repair-it-automatically-or-stop- 7 loading-at-0/3159

And if not, here you have instructions on how to change the DLL manually, look for the one that is most suitable for your system.


Thanks for answer.
I am in Graphic rendering field also around 30 years (using Lightwave 3D since v 4.0…so from the beginning)
I am also user of Unity (using DXR system…similar to D5) I just wanted to play for while with D5 but it looks like developers has problem with some parts of this software. For me is big risk to use UNSTABLE software for commercial work but D5 uses ReSTIR which I am interesting in.
Wil try these solutions from you…but doubt that will help. This behavior of software should be fixed immediately…I understand missing compatibility or not enough hardware resources but this behavior of software I faced first time…


It’s good to hear from experienced people like you, I also use Unreal, and I know that if you come from that world, D5 will always feel small.

Even though D5 is based on Unreal 4, it is far from the quality of Nanites and Lumen.

D5 is simpler and more practical for me, in my workflow, but I know the things I miss.


Opps, my mistake, I read quickly and confused Unity with Unreal, but the same thing, although Unreal is ahead in the latest versions, Unity has excellent quality.

I bought several ArchVizPro scenes from the Unity Store to try with Quest 3, which look amazing, something that D5 still needs to reach that quality.


Really sorry for all your problems. Could you show me a screenshot of your dll issue? BTW, we also provide remote support, if you are willing to accept remote support, please contact me. We provide remote support from 10.00 am to 18.00 pm HKT on weekdays.

Thank You!
Not necessary, it was simple curiosity from my side to see how D5 perform.
I cannot use D5 for other more important reason: you have no support for Lightwave file format (lwo).
I am user Lightwave 3D since 1995 and of course I am not willing to change it.
Also I am user of Unity and DXR system (HTrace) and Path Tracing engine with ReSTIR: TrueTrace for 4 years now.
here you can check my free work gallery:

But…if you are interesting to add lwo format support in D5, that will be great (I can help with this)

Thanks for your advice. We have always been committed to supporting more formats. We will consider your suggestions. :heart: