Sketch introduced a Safe Mode feature when they released version 51. If Sketch crashes, the next time it is opened, it’s in Safe Mode, meaning plugins are disabled.
Could Not Connect to Abstract Plugin message should resolve if you enable the Abstract plugin in Sketch again (Sketch > Preferences > Plugins). You can also restart both Sketch and Abstract and this should re-enable your plugins.
Crashes aren’t fun and they do happen on occasion. It could be Abstract, Sketch, or even another Sketch plugin.
Help us discover the source of any crash by copy/pasting the crash report into a TextEdit document. Then send the crash log to the support team.
Crash reports are automatically available on your computer, too. Use Spotlight to search for this folder and share crashes specifically related to Sketch or Abstract: