Hi Dan,
This is one of the very few issues that is only partially converted by ss_trans.
When you ran ss_trans, you should find in the warning.sso file a message like this:
The R1_offset parameter is now the regime parameter and it must not be estimated and should have value of 0.0
Instead, time-varying offsets to the regime parameter can be estimated; and a block for doing this has been created
you will need to manually create the parameter line for that block or turn autogen value to 0 for SR_parms
That warning file may well also show you some additional issues that were improved with 3.30.
The change from the unique R1_offset parameter to a generic block parameter was part of the effort with SS3.30 to unify the code for time-varying parameters for biology, spawner-recruitment, catchability and selectivity. The benefit for spawner-recruitment is that you now can define multiple blocks as needed.
Rick