Main mouse click stops working

Some users have reported an issue in which the "left-click" (main mouse click) does not function. This occurs for both the internal trackpad and external mice.

coolerthanice1 writes:

"Today I plugged my Mac Book Pro into my HD tv [and] everything worked fine...[Afterwards] I disconnected the TV and closed the screen. Later, I opened the screen and found that my mouse does not work. Right clicking does but not left clicking. The trackpad works for scrolling, moving the mouse, etc. even two-finger clicking for right clicking works. Option clicking does not register a right-click. I have noticed also that nothing registers the mouse as hovering, links on websites do not change the cursor to a hand, the dock doesn't pop up the name of the program I am hovering over. An external mouse has the exact same problem, left click works and right click doesn't."

This problem persists despite users restarting their computers, though mouse button works fine at the login screen, indicating that the problem is software-related. The only way users have been able to get their mice working again is to reconnect the external display (TV) and then disconnect it again. Some have speculated that Bluetooth input devices in close proximity to the computer have been discovered by the computer and interfered with the mouse settings; however, other users have had this issue with Bluetooth turned off, so while Bluetooth devices may be the cause for some users, it's not the sole cause for this problem.

It seems this problem may be in part due to some sort of lag or buffer fill-up that may suddenly get released, as one user claims this unresponsiveness occurred and then resulted in all his click and drag operations happening all at once and very swiftly, with windows closing and flying all over the screen according to his previous click sequences. This indicates the problem may be due to a hang in the driver software that suddenly gets resolved, resulting in all the previous clicks stored in an input buffer to get registered.

Fixes

Turn off Bluetooth if no devices are being used If the computer is not using any Bluetooth devices, turn the connectivity option off in the Bluetooth menu. This menu can be enabled by going to the Bluetooth System Preferences and in the "Settings" tab selecting the "Show Bluetooth status in the menu bar" option. In the menu, either disable Bluetooth if no devices are needed during alternate setups such as connecting the computer to a television. Alternatively, urn off Bluetooth devices in close proximity to the computer

Reset any USB connections Beyond Bluetooth, if users have a USB input device that is constantly registering a mouse click, this may prevent other attached or internal devices from registering the click as well. As such, users may benefit from disconnecting any USB devices that are attached to the computer, including hubs. If the mouse returns to normal then users can troubleshoot individual attached USB devices.

Perform standard maintenance Reboot the computer in safe mode by holding the Shift key at bootup, and then perform a permissions fix on the main boot drive using Disk Utility to ensure essential system files are properly accessible. Next, reboot the system. Additionally, users might try resetting the computer's PRAM by rebooting and holding down the option-command-P-R keys all at once until the computer resets and makes the boot chimes again. If the problem still persists, try creating a new user account to test the mouse behavior in, and if things work properly in the new account then users can troubleshoot account-specific system settings such as login items, or locate and remove any bluetooth-related preferences files from the users/username/Library/Preferences/ folder

Resources