What does this error mean?
eBay will send this error if your description has too much content (has exceeded the maximum character limit).
This also includes the HTML code needed for design templates and description formatting.
What is the character limit for eBay descriptions?
An eBay description's max-character limit is 500,000. This may sound like a lot, but HTML styles and formatting require a lot more space than many may realize.
How to fix:
These are a few steps you can try. Doing one or two of these will work in most circumstances.
Remove some featured items from your design template.
Hide or delete extra blocks in your design.
Remove unessacary text in your design template or description.
Check the item description for extensive formatting (tables, widgets, and other special elements may require a lot of HTML code)
The goal is to lessen how much content is in the description area.
While a lot of text could be the cause, templates and formatting code uses much more space than text alone.