[OS X TeX] TexShop hanging

["M. Tamer Özsu"]

I have had this problem off and on, but now it is really bad — almost every other run hangs in the middle of compiling. I am in 10.14.4 with TeXShop 
4.27 and I am compiling using pdflatex. I have %% !TEX TS-program = pdflatexmk at the top of my file. I tried the same file using texstudio and it compiles without problems, so there is something in my TexShop setup probably. Any suggestions of what I can try?

Many thanks.


==Tamer