https://forge.codesys.com/forge/talk/Engineering/thread/5e248a0c1b/2026-08-10T14:24:10.421000ZRecent posts to Codesys Installation problem2026-08-10T14:24:10.421000Z2026-08-10T14:24:10.421000ZTimvHhttps://forge.codesys.com/u/timvh/https://forge.codesys.com8f964726041c4e0be13b7295b1f0b944b73cf21d

<div class="markdown_content"><p>Instead of complete VM's, you could also create a sandbox installation using the CODESYS installer.</p></div>

2026-08-10T00:44:59.761000Z2026-08-10T00:44:59.761000Zdhumphrieshttps://forge.codesys.com/u/dhumphries/https://forge.codesys.comd993d52f668f356a79e601034821407cabcf273c

<div class="markdown_content"><p>Installing codesys has been the biggest point of frustration for me and is the reason I'm currently working on building a VM just for the codesys engineering software so once I get a working installation I can copy the VM to new workstations instead of fighting with the installer every time I get a workstation upgrade. The best advice I've gotten in the past is to uninstall everything and start over, this is successful 50% of the time. Also don't install the latest version it's usually less stable than an older one ironically.</p></div>

2026-06-16T15:24:47.301000Z2026-06-16T15:24:47.301000Zanthony-phttps://forge.codesys.com/u/anthony-p/https://forge.codesys.com52c518c2ceb5cb1f94f697d0d9495f8ead7b8fec

<div class="markdown_content"><p>Hello,<br/> I'm trying to install Codesys SP21p6 (but the error occurs in SP22 too for eg.) but it fails to install ApplicationComposer.<br/> Trying to install myself (version 4.4.0.0 or 4.5.0.0) by clicking 'changing the installation' from the Codesys Installer isn't better.<br/> The only message I get is <br/> "An error occured during the installation: The file <span>[..]</span>/ApplicationComposer.plugin.dll isn't a valid plugin"<br/> How is that? The installation went good the last time before a reinstallation...</p> <p>However, installing the version 4.3.0.0 seems to be successful without knowing what's the difference.</p> <p>I already tried to :<br/> - Restart my computer<br/> - Delete all temporary files in C:\ProgramData\CODESYS\Temporary Files<br/> - Download the package from the store<br/> - Compare the ApplicationComposer.plugin.dll from another computer (where the installation is OK) and it's exatly the same</p> <p>For your information, I can install other packages, such as Codesys CFC</p> <p>Can you help me? Do you have any idea of what could be the problem?</p></div>