Voltage regulator (LM350) gives no current
There are a few possibilities:


The resistor is not pulling enough current for your meter to measure. 8V across 650k&Omega; is 12.3&mu;A, a fairly small amount. Some meters may not be able to measure this small current.
You may have forgotten to move the meter's test probes to the appropriate ports on your meter. Some meters require you to move one probe to another port to measure current, and often there may be more than one port: one for higher currents and one for lower currents.
You might be using a range that is too large, for example a 10A range, when a 200mA range would be more appropriate. (Varies by meter.)