Android: Could not load assembly 'xxx' during startup registration

I'm trying Syncfusion (charts) and in the Android project after deploying I get

Assembly Loader probing location: 'Syncfusion.SfAutocomplete.XForms.Android'.
Could not load assembly 'Syncfusion.SfAutocomplete.XForms.Android' during startup registration.
This might be due to an invalid debug instalation.
A common cause is to 'adb install' the app directly instead of doing from the IDE.

I readded the reference but that didn't help. Furthermore I tried to disable fast deployment without success. How can I find out what the cause is? Building the app works fine.