[Not enough free space - When there is enough]

@dankshit The files are still in the resilio debian repository, but you can't browse them.

http://linux-packages.resilio.com/resilio-sync/deb/pool/non-free/r/resilio-sync/resilio-sync_2.5.13-1_armel.deb

http://linux-packages.resilio.com/resilio-sync/deb/pool/non-free/r/resilio-sync/resilio-sync_2.6.1-1_armel.deb

But don't use either of those, instead do what @thePowerOfDot suggests and change the free space option.  I had accidentally upgraded to the current version and the out of space error returned and I was able to resolve it with the free space change.

 

[Not enough free space - When there is enough]

I see the same error using resilio-sync_2.6.1-1_armel.deb on a Pi Zero.  I downgraded to 2.5.13-1 and that resolved the problem.