iPad apps are not installing either from self service or auto install.

Seen this a few times lately - if you issue a Send Blank Push command, it usually jogs them on. 

Also, do a search for any device (computer or mobile device) that has a blank serial number. If a device has a blank serial number, it crashes the license monitor. Usually doing an inventory update on the offending device to repopulate the serial number will get things working again.