Not sure if this a bug caused just by this train or an issue relating to upgrades in general, so I put it in this board rather than the pakset bugs.
When trying to upgrade the merchant navy class selecting the br standard tender causes the game to crash with the following meesage:
QuoteFATAL ERROR: vector_tpl<T>::[] - PK14vehicle_desc_t: index out of bounds: 2 not in 0..1
Aborting program execution ...
For help with this error or to file a bug report please see the Simutrans forum at
https://forum.simutrans.com
This does not occur when sending the consist to the depot to replace the loco manually.
Does anyone know another upgrade like this so I can test this? Perhaps the A1 to A3?
Thank you for your report. Do you have a saved game in which this can reliably be reproduced?
RanRan has recently produced a fix for a bug matching this description. Can I check whether this resolves this issue?