The only way you would have spreads with more than two pages is if you turned of page shuffling. Is there a reason that you need spreads containing 10 pages rather than the normal 2?
And re-enabling page shuffling should allow you to add pages, but if there is a requirement to have 10-page spreads it is going to make a mess.
Thanks for your answer.
I don't need page shuffling, it just happened to be that way. I'm taking over a project from somebody else and kind of pushed into the situation
Without to much knowledge of ID.
Where to I turn off page shuffling?
You need to turn it ON, not off.
Open the Pages panel and select all the pages, then open the panel flyout menu and be sure both Allow Document Pages to Shuffle and Allow Selected Spreads to Shuffle are checked. Answer NO when asked if you want to preserve the current arrangement.
You might want to do this on a copy of the file, just in case it gets really ugly to deal with.
Thanks Peter, I'm back on track