# Run Parallel commands after 10.13.5 OSX upgrade?

GROUPS:
 Hi,Yesterday I upgraded OS X to 10.13.5, on my mid 2012 MacBook Pro. Today I found out that neither Mathematica 11.3, nor 11.01 is capable to run Parallel command, like ParallelTable[] at full speed. Instead of the usual 99.5% CPU usage per kernel, I see 0.5% CPU usage, so practically I am unable to run any of my programs. If I inquire the status of the Parallel Kernels from the menu, the program is falling into an endless loop, so I have to kill it after some time. So, I am wondering if it is only with my particular machine or it is a much more widespread phenomena. Thanks ahead, János
 I did a quick check using some of the examples. ListPlot[ParallelTable[ Total[FactorInteger[2^i - 1][[All, 2]]], {i, 150, 300}]] is working (the example had limits {150, 190} so I increased it.) Activity monitor shows 4 threads of WolframKernel running at 99.9%, The function is still processing -- I should have made the upper limit something more reasonable -- but it is sufficient to say that ParallelTable is working. With the example limits, it returned relatively quickly.Running an iMac (2017) with a 4.2 GHz Intel Core i& and 32 GBytes RAM.