I have attached an event receiver to Wiki Pages Library ItemAdded and ItemUpdated events.
The ItemUpdated event fires when I add/create content from OOTB designer view (Insert, Text Format, etc) then check in.But when I copy past content from Wikipedia and check in the ItemUpdated event doesn't fire.
But the contents are saved in the page and version is updated but didn't trigger the ItemUpdated event. Didn't find any errors in ULS. Following is the page I tried to copy content from https://en.wikipedia.org/wiki/Forest
I drilled down to this issue and below is my finding. I still believe this is something to do with content(Char encoding).
Following is the part of the content that user copy past as the wiki page content.
Insurance is intended to protect an already existing or growing estate, not to create an estate at the time of death. Life insurance
it contains some formatting chars.Below is how it shows in word. I have highlighted the char(between death. Life) that stops the event receiver firing. When I remove that char from this paragraph event receiver works fine.