This issue might be with your Skript version but I am unsure.
I personally haven't used that version since its been unmaintained and unsupported for about 4 years now.
Most of the community uses Bensku's fork.
He is the current maintainer of the project.
His goal was to bring a working Skript version into the MC world of 1.9+, that being said, its not officially supported on 1.8.8 but it has been said to work.
I would highly recommend updating. The latest version that has still been said to work is
Skript 2.2 Dev37c
Good news and bad news:
Good News = By updating you gain a lot of new features, actual support, new syntaxes, etc.
Bad News = There have been a decent amount of changes in Skript since Bensku took over the project. Due to that some of your skripts may be "Broken" .... its not generally the case of your skripts being broken, as much as its the addons being broken. Some addons, like SkQuery and Tuske have been forked by members of the community and updated to work on Bensku's fork of Skript.
Ex:
SkQuery was forked by lime, and the current working version for Bensku's fork of Skript is
SkQuery-Lime
I highly recommend updating all your stuff. It may seem like a trying task right now, but it will be well worth it in the long run. Plus by using updated plugins you will be able to get proper support
Special note:
The client block thing was added into Skript in Dev37c which means you wouldn't even need SkQuery for that. Plus it works MUCH better than the SkQuery syntax
Send Block Change