I have faced this Robocopy error many times:
2010/03/20 11:48:37 ERROR 5 (0x00000005) Copying File C:\Foobar.pdf Access is denied. Waiting 30 seconds...
The reasons for this error are many and the fixes depends on the reasons:
Check if the destination disk is full.
/COPY:DT option. By default, Robocopy copies using the option
/COPY:DAT. This copies the Data, Attributes and Timestamps.
/COPY:DT ignores the Attributes.