After first mail message I read each time I open Mail, I lose the functionality of my mouse. No highlighting, no quick peek, no copying.
Commands work: I can use CMD+A to highlight everything for example.
If I forward the mail message, I regain all functionality in the active window (ie, in edit mode, not read mode).
This is new behavior.
I'm running El Capitan OS X 10.11.6
Is there a possibly corrupt file I can delete?
iMac Pro
El Capitan is rather old. Can you upgrade this Mac to High Sierra, or later? An iMac Pro supports High Sierra, as well as the current Mojave release—it also doesn't support El Capitan and which where this question has been posted, so I'm not sure which Mac is involved here.
As for other sorts of misbehavior, there are lots of add-on packages that play in the input I/O path.
Try booting into Safe Mode, and see if the problem exists there. Safe Mode disables most add-on packages.
If you'd like us to look at this, please download and invoke and post the output of EtreCheck here, opening a reply and then using the button that looks like a printed page to open a text input box that's usually large enough to paste the EtreCheck report.
El Capitan is rather old. Can you upgrade this Mac to High Sierra, or later? An iMac Pro supports High Sierra, as well as the current Mojave release—it also doesn't support El Capitan and which where this question has been posted, so I'm not sure which Mac is involved here.
As for other sorts of misbehavior, there are lots of add-on packages that play in the input I/O path.
Try booting into Safe Mode, and see if the problem exists there. Safe Mode disables most add-on packages.
If you'd like us to look at this, please download and invoke and post the output of EtreCheck here, opening a reply and then using the button that looks like a printed page to open a text input box that's usually large enough to paste the EtreCheck report.
Mouse stopped working in mail preview pane
