I'd like to have a closer look at that error message please.
Generate the error message again. While the error message box is open, hold down the Alt key and hit the PrtSc key. Paste the screenshot into an image file (using a program like Paint), and save the file.
Start a reply here and click the wee camera icon at the top of the reply window. Click "Choose file", browse to the image file, select the file and click "Open". Now click "Insert file" to insert the screenshot into the reply.