Collapse Sequences Failure

I am trying to carry out the collapse sequences function under the FASTA/FASTQ tools, however it doesn’t seem to be loading. I have tried running other functions, which run fine, however when I go to use the collapse function it doesn’t run. I have tried re-running it a few times for different datasets and in different histories however this doesn’t seem to be resolving the issue.

Any help with this would be great.

Thank you.