Would you be kind enough to state what operating system you are using and what version number of Lightroom you used to have before the disappearance?
Without knowing a whole lot more detail, I would suggest you re-install Lightroom. Go to Keeping Lightroom Up-to-Date and download Lightroom and install it.
By the way, when I ask for "a whole lot more detail", that doesn't mean repeating the problem 3 times (which doesn't help us help you, stating the problem once is enough for us to help you), it means providing additional information and maybe even screen captures.
Lightroom CC 2017 disappeared from both my computers. Mac 10.11.6. I am a monthly subscriber to CC payments are current. Bridge and PS are not affected
Look in the Applications folder for Lightroom. Unless Apple has done something that would cause applications to disappear LR will be in the that Applications folder.
LR 2017 is not in applications any longer. CC has LR 2015? I can only install from Adobe Web. I do not know if this is best. We pay for a service and cannot call service on Saturday. Sucks
Sent from my iPhone
(Email Address removed by Moderator. Please don't post email addresses in replies)
There is NO LR 2017. The latest version of LR is 2015 and then the most current update to LR 2015 is .10.1