> You mean EventCalendar? That's not 2.3 compatible?

Sorry, should have tested before asking turns out the problem with DOM was also causing the problem with EventCalendar - it's now playing nice, thanks!

I've just updated my ss to 2.4rc1 and also got the trunk version of DOM.
After the update to make it work I had to change the following (core/DataObjectManager.php:647):

foreach($this->parent->permissions as $perm) {

to:

$permissions = $this->parent->permissions;
foreach($permissions as $perm) {

Otherwise I had this: ERROR [Notice]: Indirect modification of overloaded property ManyManyDataObjectManager::$permissions has no effect

I am having an issue with SS 2.3.7 and Image Gallery 2.3 branch. I have an Image Gallery Page with two Albums. I have done some debugging and found that Albums.MoreThanOnePage is using the Images Per Gallery limit as the Albums Paging limit as well. The result is that unless I have more than 16 Albums I don't get Album Pagination. Image Pagination within a gallery works fine also using the 16 limit.

That means the field has already been added to your form from another source. A lot of times that happens with legacy fieldnames, so it's really common with something like SimpleTreeDropdownField because it's based on a foreign key. You just have to get them cleaned up. As an experiment, just look at the source of your form and look for anything in there already named "LinkedPageID" (probably a hidden input). Try changing the field name to something else (even if it doesn't exist in the DB yet) and you'll see that it gets added. Usually just a namespace conflict.