I was getting an error when trying to reach Page Layouts and Templates page from site settings on one of the sites in our collection.
When the user clicks on Site Settings -> Modify all site settings -> Page Layouts and Site Templates
1) No Site template and/or Page layouts Template are coming.
2) No associated Content type group is coming , when you upload a master page in Master page gallery
I’ve checked Event Viewer on the server and found no errors for this issue.
If you create a publishing subsite, and export the site and import it into the root of the site collection, you will encounter this error.
If this the case, you can perform the following steps to fix the issue:
Site Actions -> Site Settings -> Modify all site settings. Click on Site Features under Site Administration.
Deactivate Office SharePoint Server Publishing.
Reactivate Office SharePoint Server Publishing.
Go back to Site Settings. Click on Master pages and page layouts under Galleries.
Click on Settings->Document Library Settings, click on Advanced Settings
Select Yes under Allow management of content types, Click OK.
Click on Change new button order and default content type under Content Types. Change Page Layout to 1, click OK.
Hope It may Help J