Welcome to the Community space, Lin.
I am here to provide some insights into the possible reasons behind the grayed-out tab functions in QuickBooks Desktop 2015 for MAC.
One possible reason for the issue could be the compatibility of the QuickBooks Desktop 2015 with the recent upgrade of the Mac operating system. It is recommended to ensure that the upgraded OS is compatible with QuickBooks Desktop 2015, specifically Mac OS X v10.10 (Yosemite) and v10.9 (Mavericks).
Alternatively, if there was no recent upgrade of the OS, restarting your MAC and opening QuickBooks Desktop 2015 could help resolve the issue. However, if the issue persists even after restarting your MAC, it is suggested to perform an uninstallation and reinstallation of QuickBooks Desktop 2015. This is because there might be an issue with the program on your machine that a reinstallation can fix.
I’m also adding this resource for your reference, where you can search for related articles whenever you have issues with QuickBooks: Help articles for QBDT Mac.
Come back to this post if you have further concerns or follow-up questions regarding logging in to you QBDT 2015 for Mac. I'll be here to lend a helping hand.
