X1® Professional Client Version 6.7.4

For about a year 6.7.3 (Build 4054dh) was stable.
I upgraded to 6.7.4 (Build 4054eu) for it's advantages described above.
However, I experience unexpected crashes in file search.
(For certaing search criteria, X1 does not even report an error. It just disappears.)

How do I roll back to the older release without having to rebuild the index of ~10Mio files?

Thanks
P

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