Because old versions are incompatible with the Cardano network they will not be able to sync. After 5 minutes of not being able to sync, an error will be shown and users will be propted to log a support request.
An update made by IOHK to the Cardano network on Saturday, November 17, 2018 contained a minor software update. This follows a patch issued earlier this week to remedy abuse of large addresses, which were being used to add inappropriate images and data to the blockchain.
The network is running well and at no point were user funds affected.
You must use this new version of Daedalus - you will not be able to use previous versions of Daedalus as the wallet will not fully sync to the network. All users must update to Daedalus wallet 0.11.2 + Cardano SL 1.3.2 immediately.
Note that If you downloaded Daedalus wallet 0.11.1 + Cardano SL 1.3.2. you do not need to upgrade, there is no difference between Daedalus wallet 0.11.1 + Cardano SL 1.3.2 and Daedalus wallet 0.11.1 + Cardano SL 1.3..2 except for the version number.
Old versions of Daedalus wallet (Daedalus wallet 0.11.1 + Cardano SL 1.3.1 and older) are no longer compatible with the Cardano network. Please download and manually install Daedalus from https://daedaluswallet.io/#download Automatic updates will not be available for this release.
See the Updating Daedalus wallet to 0.11.2 + Cardano SL 1.3.2 help topic for detailed instructions on how to resolve this issue.