This is the most common cause. You are switching between applications. You click back into AutoCAD and, without focusing on the command line, you type a number like "0" or "2.5" as a keyboard shortcut for another program. That number sits in AutoCAD's command buffer. Then, you start a legitimate command like COPY . AutoCAD sees the leftover "0," tries to use it as the number of copies, and the prompt explodes.
The prompt usually appears when AutoCAD is asking for a Zoom Scale Factor relative to the current view or the paper space. autocad please enter an integer from 1 to 20000
A: Create multiple arrays. For example, two arrays of 15,000 instead of one array of 30,000. Or use a dynamic block with a pattern. This is the most common cause
: The drawing file might be corrupted from being saved in a non-Autodesk application. Use the AUDIT command to find and fix internal errors, or use Recover to open the file. That number sits in AutoCAD's command buffer
Frustrating but necessary precision