Can't find or load the QT platform plugin “windows” - unable to start ACAD 2018

[finnurp]

This application failed to start because it could not find or load Qt platform plugin "windows" in "".

Reinstalling the application may fix this problem.

Get this message when I start up AutoCAD 2017 and 2018.

Have used repair and reinstall. Have uninstalled using the uninstall tool from Autodesk and then done a fresh install. Nothing helps.

I can run.as a trial but as soon as I want to register it chrashes.

Have installed all Windows and Autodesk updates as of yesterday. Chrash report have been sent to Autodesk.

Urgent help needeed

PS. I am able to run Revit.

[pendean]

Can you install Process Monitor to determine what is missing? That should help you identify where the system is looking for those DLLs
https://technet.microsoft.com/en-us/sysinternals/processmonitor.aspx

[RickFalck]

having this same issue but with maya 2018.. any idea for solutions?

[Anonymous]

I installed the open source Qt library (from https://www.qt.io/download) on my Windows 10 pc and rebooted, and was then able to download parts from https://autodesk-fusion.partcommunity.com/3d-cad-models/sso into Fusion 360.

[ksullivan]

I found a strange solution for this, it showed up on a couple of our computers lately, the installs were in place and working then randomly stopped working. No patches had been applied no apparent normal causal issues seen all processes looked fine.  uninstall/reinstall did not work.  When I looked at the 2020 solution https://knowledge.autodesk.com/search-result/caas/sfdcarticles/sfdcarticles/Error-writing-to-file-C-... I realized this process issue may be connected to the online data sync.  I couldn't even launch A360 to sign out user.

With previous issues regarding A360 sync we did the following to force a sign out.

By renaming the following folders with a ".old" 

C:\Users\(username)\AppData\Local\Autodesk\Web Services
C:\Users\(username)\AppData\Roaming\Autodesk\WebServices

Then a relaunch.

It worked no reinstall needed. 

Not sure if this will help but in these cases it did.