Missing Editing Options in Lightroom Develop

[#1]

For the first time when I tried to use the editing options in the Develop module in Lightroom - selecting Photo - Edit In - there is only ON1 or Photoshop options. I used to have several other options, such as Colour Effex 4, Silver Effex 2 etc. These have now disappeared.

[#2]

One cause may be you have changed the Preference to "Store Presets with the Catalog".

NIK installs by default to the 'Global' Presets folder location and so will not appear if your preference is "...with the catalaog".

(I would expect the same with ON1, maybe??)

Have you made any other changes to your system recently?

Have you moved, renamed or deleted the NIK install folders?

And your- LrC version? OS version?

[#3]

I haven't changed the Preference to "Store Presets with the Catalog". I wouldn't know how to do this. No other changes have been made. I have been editing photos every day for weeks and this only happened yesterday for the first time when I opened a photo in Lightroom Classic and tried to find the Presets in the usual way - Photo - Edit In - Silver Effex Pro 2, Colour Effex Pro 4 etc. in the dropdown box.

[#4]

Is this the only "plugin" that is not working for you in Lightroom Classic?

Can you reinstall the NIK suite of plugins again?

[#5]

The only plugin that is available to me is the ON1 develop modules or Photoshop. I suppose I will need to locate the NIK suite again and re-install. Just wondered if anyone else has experienced this change?