I don understand the error but this may help
A MOV only move 1 word to a word of the same type
A MOV also moves the original data / Bits to the new location
A COP move arrays to and array of the same type the limit is 256 words at time
A COP copies the data to the new to the new location leaving the original data in tact
the copy is a better way to copy data len of 1 will copy 1 word
the other thing AB treats all strings as arrays of values a string of 10 characters will be an array of 10 sint ( ASCII)
when I set you the simulation of what I think you are trying to do I could only copy 3 strings of the array at a time the error I got back said I exceeded the 256 word limit
Working with string is a little different and requires some thought