CROSS APPLY Error: Incorrect syntax near 'M'

To use APPLY, the database compatibility level must be at least 90. Check the compatibility level and update it if required:

http://copypastenet.blogspot.com/2010/12/compatibility-level.html

If you can't update compatibility level for some reason, replace CROSS APPLY to Join:

select f.* from TableM M

cross apply dbo.udf_MembersOfM (79706,@cDate,M.ID,null,null) f 

-->

select f.* from TableM  M

inner join dbo.udf_MembersOfM (79706,@cDate,null,null,null)  f on and M.ID = f.ID