The fuse4x kernel extension was not loaded.

Try:

sudo chgrp -R wheel /Library/Extensions/fuse4x.kext

and a reboot.

Keep popping up after that.

Realy anoying.

The kext is from MacFUSE (or similar software that allows OS X to write to "windows-formatted" drives), which you must have installed at some point before updating. What's probably happening is that apps that make system-level changes (as MacFUSE needs to do to allow NTFS to be natively written to) are running afoul of SIP (System Integrity Protection) in 10.11.

If you don't need it anymore then you can just delete the kext with the following command:

sudo rm //Library/Extensions/fuse4x.kext

And reboot to see if it's resolved.

Having the same issue. Both suggestions did not work.. 😢

Hmm seems to lost my post.

But gave up earlyer, formated.

Installed 10.10.4 and everything was working well.

Untill i had to try when Apple lay out the public El Capitan and BOOM there it was again.

Now i have just have to hide all six popups windows and thats it.

What a heck kind of program uses this Fuse thingy?

So weird, have a new MacBook Pro where i have been testing Dev 1,2 and 3.

Same software but no popups.

Do you happen to use Transporter?

I booted the mac into SafeMode and found no issues. Started each program individually and found Transporter to be the cause.

You beat me to it, yes its Transporter that causes it.

Gonna write Connected Data about it.

Already filed a note with Connected Data. They haven't tested anything with 10.11 yet. They are also using Fuse4x circa 2012 not OSXFuse which has a test version (2.8) out for 10.11.

This problem is caused by the System Integrity Protection. To remove the messages you need to turn off SIP. However, this is a global move and all protections are turned off.

how do you turn of SIP ?

my iMac does not start with my DROBO connected.

how do you turn of the Systeem Integrity Protection ?