Hi, I suggest that you should reinstall the component and please remember to click on the button "Continue Installation", then finish the installation steps.
After that try to create articles again.
Unfortunatelly, it did not help. I tried the installation steps a few times without the sample files, and one time with the sample files.
Without the sample files, I get into the Article overview, but if I try to create a new article, I get the error " Class 'TZ_Portfolio_PlusPlugin' not found".
With sample files, I cannot even access the Article overview. The dashboard is fine as before, but when I press the Article Menubutton on the left, I get the same error: "Class 'TZ_Portfolio_PlusPlugin' not found"
I am using Joomla-Version: 3.10.8 and wanted to install the newest version of TZ Portfolio available (2.5.7).