Lcd_Out(1,1, "ReadSum = " + #ADCReadSum) 'Ok
Ok, it compiles fine, after the name of a user-defined function "Function and Proc" there can't be a space between the name and the parentheses.
FunctionName+space+(argument) = error.
I installed v5.76 and after correcting line 68, compilation did work ok.
Gee, what a stupid little mistake that was with the blank before the bracket!
Thanks everybody for your help.