Back end error of Alpha Red

[minirookie]

Hi, I hope this post finds everyone well.

I used the Alpha-Red to predict a complex structure of Fab-bound TGF beta (dimer) and ran into this error:
ERROR: failed to validate flag line: '-parser:protocol @dock-xml-ref ' due to presence of '@', aborting...

I double-checked my sequence input and made sure there were no errors: 4 peptide chain sequences as input (total residue 456), separated by ":", with the partner flags "HL_ab". The result page warned the job execution was aborted, and the running log showed the run stopped after 5 cycles of seeding :

2026-03-23 19:42:36,620 alphafold2_multimer_v3_model_1_seed_000 took 11677.0s (5 recycles)
2026-03-23 19:42:36,855 reranking models by 'multimer' metric
2026-03-23 19:42:36,855 rank_001_alphafold2_multimer_v3_model_1_seed_000 pLDDT=83.1 pTM=0.572 ipTM=0.438
2026-03-23 19:42:37,299 Done

Can you fix this error? Thanks!