Disconnect the hose at the vac and see if you can blow through it. If not, take a broomstick and push it through the clog-sock, rag etc. If the hose is open, look in the hole where it connects for obstructions. Finally, take out the brush assembly and see if something is stuck in the vac port. 99% of the time it is an inline obstruction, easily fixed. Good luck.

The hose is clear and I'll try the brush assembly.