Bonsai Trees version: 1.0.2-b63
Forge version: 14.23.2.2618
I am not using Optifine: I am not
Link to Crashlog: Not getting a crashlog
Screenshot (if possible): n/a

Description of the problem including expected versus actual behavior:

Tried both left clicking and right clicking, and shift+rt & shift+lt clicking saplings on both of the bonsai bases, and neither would accept a sapling.

I too have this problem, however it is in modern skyblock 3 departed. Version 1.0.2-b63

Did you try both off- and main-hand?

I will look into it when I get home from work.
What other mods are you running? Do you maybe have some skill-restriction mod or something else that might be preventing block interactions with bonsai pots?

I am having the same problem, unable to plant it on either the normal or hopper version. I was able to on my single player world, but I am unable to on a server. Playing version 3.1.5 and kitchen sink mode. I've also tried multiple saplings, vanilla and modded.

This is fixed in version 1.0.3 of the mod.