Hey,
for Apple user there seems to be an bug report (found it in Desktop app 2.5.1 (build 10818) on MacOS Mojave 10.14.2 crashes a lot) to the developers of the sync client available below.
If i understand this link correctly the developers are not able to reproduce this and crash reports seems to not contain enough information as well. But it seems some additional questions where asked there, maybe you can contribute this info here: