Error in Code Line 0; Subscript out of range

I try to run an input file in DirectRT with two different randomization techniques. Some trials are randomized by the wgr function, some other trials are randomized via rand(1,2,3,4).bmp in the stim column. Additionally, there are some skips and jumps in the file, and I have combined skipping and jumping with my rand(1,2,3,4).bmp stimulus. Unfortunately, DirectRT does not run the file. It stops after starting the file immediately, showing a black screen. When I abort with esc, I get the message Error in Code Line, Error #9. Subscript out of range.
Can anybody help?
Thanks in advance, Sabine

Can you simplify the input file to about 10 trials or so (but where it still produces the same result) and then post it as an attachment? I'd be happy to take a look at it.