This is really strange. I uploaded a new version of my packaged app. Everything compiled and the tests run green.
But when parts of my code are executed by the customer they receive error like this one:
Previous load of class failed: XYZ_TriggerHandler: line 6, column 29: Invalid type: InsertDeliverySchedulesOnVolumeLinking
and indeed in the customer org the class show
NMESPACE.InsertDeliverySchedulesOnVolumeLinking does not compile.
Could it be that a 38 character long class PLUS the additional Namespace can lead to a too long class name?