I have an interesting problem with the BSC Maxis blocker. In the process of troubleshooting, I have redownloaded, so I know it's the most recent version of the mod. The issue is that it's only allowing one building to grow, Simgoober's Jiffy Lube. I know that's not the only growable I have installed; I have the entire Small Town USA collection installed, not to mention all of the other SG growables that the Jiffy Lube came packaged with. I tried only making 1 tile wide zones, (the Jiffy Lube is 2x2), but then nothing at all grows.
I also have the Residential and Agricultural versions of the Maxis Blocker installed, and they have no similar issues.
EDIT:I am on a Mac, but in my experience, that is rarely the cause of problems with mods and their functionality.
I find that very odd as I use those all the time and have never had any problem with only one custom building growing. It may indeed be a Mac problem but as I don't have a Mac I can't help, sorry.
I don't know if Simgoober's lots are stage 1, but make sure you have stage 1 custom content installed or nothing will grow
Also check that you have all building styles set to grow, as maybe the others are in a style you have turned off.