This message is generated when the specification of the number of terms to compute in a series is not an integer or cannot be represented as a machine integer on your computer.
Off[message] switches off the message; On[message] switches it on. For example: Off[Series::serlim].
Examples
Basic Examples(1)
An error occurs because the limit specification is a symbol rather than an integer:
This shows a valid specification for the number of terms in a series: