Thanks for reaching out. Sorry about the trouble with the dissolve filter in Photoshop. We're here to help.
Could you please share the version of Photoshop (Help > About Photoshop) and the version of Windows on your computer? What happens when you try to select the dissolve filter or when you use the shortcut? Are the filters greyed out? What type of file format are you working on? Since when are you noticing this issue?