I add this as answer to the original question, but it takes into account the other answers/comments as well. I did some quick and dirty tests, and it seems that CameraRaw 9.9 or 9.10 is NOT the culprit. The culprit is Photoshop 17.1.0. When CameraRaw gets installed, it will be called from all installed Photoshop applications. I have CameraRaw 9.10 installed. • Starting Photoshop CC 2015.5, opening a TIFF, switching to 32 bit --> CameraRaw filter can be selected, and it opens the picture. • Starting Photoshop CC 2017 (version 17.1.0), opening a TIFF, switching to 32 bit --> CameraRaw filter (plus a bunch of other filters) can not be selected (because greyed out) Conclusion: Photoshop CC 2017 (version 17.1.0) has a severe bug, as a bunch of filters are no longer working with 32bit pictures. The version of the CameraRAW seems to be of no relevance (I can not test that, because there is always only one CameraRAW plug-in/filter available, system-wide). BTW, there are other serious bugs in version 17.1.0, in connection with the CameraRAW plug-in. Possible workarounds (note, this is not from Adobe; I am just a simple user, using some logic): a) downdate Photoshop to version 17.0.1 (which apparently worked, otherwise, this thread would have come up way earlier) b) do the processing with the CameraRaw filter in 16 bit. @davedwyervideo: The decision whether and when to fix a bug is taken by persons most likely not following this forum; Brett N is just the messenger. Depending on how critical a bug is, an immediate fix may come up, otherwise, we'd have to wait until the next "regular" update (that's my experience with Adobe and Acrobat).
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