Here's my test:

-loaded 938 MF9:2 Undulator (this is the second Undulator preset)

-stored to user memory as #2

-reloaded from User memory

-press PARAMETER twice

-press ROUTING and select "series"

.press PARAMETER one more time

-press PROGRAM to select which algorithm to copy to the B block

-selected 161 Reverse Crystals & press LOAD FX B to load it

– no freezing occurs

BUT "This parameter cannot be modulated: Press any key to continue" appears…and shouldn't.

What algorithm did you choose to load in the FX B block?

I can't replicate the freezing here.

best

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