UDP symbols imported from DWG files or other external sources can contain extremely complex geometry — polylines with tens of thousands of control points — even when the symbol looks simple on screen. A single such symbol can make a project file several megabytes in size and cause report generation to fail or rendering to become very slow.

Diagnosis: check your project file size. A simple project with a handful of drawings should be well under 1 MB. If it is several megabytes, open the affected UDP in the Symbol Editor and check the Shape Count. Thousands of shapes indicates a problem. Look for individual lines with 50,000 or more control points.

Resolution:

• Delete the overly complex lines and curves in the Symbol Editor.
• Replace imported polylines that represent straight lines with native Line objects.
• Replace Bezier curves that approximate circles with native Arc objects.
• Re-save the UDP. Project file size and render speed should drop dramatically.