1. Close all QINSy related aplication.
2. Please rename the following DLL's in your Qinsy 8.18.4 or 8.18.5 installation folder (c:\Program Files (x86)\QPS\QINSy\8.18.5\) by adding a post fix "_org" to the DLL name.

* Qt5Core (i.e. to Qt5Core_org.dll)
* Qt5Gui
* Qt5Network
* Qt5Widgets
* Qt5Xml  


3. After you have backed up/renamed the original DLL's copy the DLL's in this folder into your installation folder.
* Qt5Core (i.e. to Qt5Core_org.dll)
* Qt5Gui
* Qt5Network
* Qt5Widgets
* Qt5Xml  

To 
- c:\Program Files (x86)\QPS\QINSy\8.18.4\
- c:\Program Files (x86)\QPS\QINSy\8.18.5\
