HI ALL …
I have found the fix to this issue :
to get back the Reverence presets … will be missing when you update Halion Sonic from 1.5 to 1.5.2
just goto C:\Users.…\Documents\Steinberg\HALion\Sub Presets\Fx\Reverb\REVerence
which is the place that you use to put your user presets … and copy to it the contents of the folder :
C:\ProgramData\Steinberg\HALion\Sub Presets\Fx\Reverb\REVerence
that should bring all the presets back.
hope that helps … took me many hours just to figure it out … but good to be helpful ,
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I have installed the Halion 4 update 4.0.1 (64 bit version) , and it says in the release notes that the missing Reverence presets have been added.
This does not seem to be the case 
.
when loading a Reverence instance :
1- preset field is empty
2- only one Impulse response is available : English Chapel a …
clicking on the small down arrow-head (to see the other presets) does not do any thing … no dropdown list is shown …
not sure if I am the only one … I tried to refresh the folders under VSTSound … thinking that It may need to be updated … but I can see the Reverence presets in its folder in Mediabay … so presets are there … Halion 4 cannot see it … nor change the Impulse responses …
feedback is appreciated.
** I work as a software QA Analyst .
Thanks
A.H