getting errors when run this program

Hi There, I am following the website install guide to install and try a demo diagram. but I am getting below errors, could you provide some help on fixing this error? I am running it on MacOS Catalina.

python3.7 demo.py Traceback (most recent call last): File "databasechoices.py", line 10, in EC2("web") File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/diagrams/init.py", line 147, in exit self.render() File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/diagrams/init.py", line 189, in render self.dot.render(format=self.outformat, view=self.show, quiet=True) File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/graphviz/files.py", line 209, in render quiet=quiet) File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/graphviz/backend.py", line 206, in render run(cmd, capture_output=True, cwd=cwd, check=True, quiet=quiet) File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/graphviz/backend.py", line 172, in run output=out, stderr=err) graphviz.backend.CalledProcessError: Command '['dot', '-Tpng', '-O', 'simple_diagram']' died with <Signals.SIGABRT: 6>. [stderr: b"2020-09-10 14:05:35.547 dot[4726:59127] +[__NSCFConstantString length]: unrecognized selector sent to class 0x7fff88cd88e0\n2020-09-10 14:05:35.547 dot[4726:59127] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '+[__NSCFConstantString length]: unrecognized selector sent to class 0x7fff88cd88e0'\n*** First throw call stack:\n(\n\t0 CoreFoundation 0x00007fff313b0b57 __exceptionPreprocess + 250\n\t1 libobjc.A.dylib 0x00007fff6a1f75bf objc_exception_throw + 48\n\t2 CoreFoundation 0x00007fff3142fb37 __CFExceptionProem + 0\n\t3 CoreFoundation 0x00007fff313153bb forwarding + 1427\n\t4 CoreFoundation 0x00007fff31314d98 _CF_forwarding_prep_0 + 120\n\t5 CoreFoundation 0x00007fff312c8588 CFStringCompareWithOptionsAndLocale + 72\n\t6 ImageIO 0x00007fff341f7686 _ZN17IIO_ReaderHandler15readerForUTTypeEPK10__CFString + 50\n\t7 ImageIO 0x00007fff341f74b1 _ZN14IIOImageSource14extractOptionsEP13IIODictionary + 155\n\t8 ImageIO 0x00007fff34224ce1 CGImageSourceCreateWithDataProvider + 213\n\t9 libgvplugin_quartz.6.dylib 0x000000010e16fc5c quartz_loadimage_quartz + 224\n\t10 libgvc.6.dylib 0x000000010e0b49bd gvloadimage + 269\n\t11 libgvc.6.dylib 0x000000010e0b3a21 gvrender_usershape + 956\n\t12 libgvc.6.dylib 0x000000010e0e16ba poly_gencode + 2168\n\t13 libgvc.6.dylib 0x000000010e0edb41 emit_node + 1025\n\t14 libgvc.6.dylib 0x000000010e0ec8d0 emit_graph + 5048\n\t15 libgvc.6.dylib 0x000000010e0f1e4c gvRenderJobs + 4936\n\t16 dot 0x000000010e0a7d62 main + 697\n\t17 libdyld.dylib 0x00007fff6b39fcc9 start + 1\n)\nlibc++abi.dylib: terminating with uncaught exception of type NSException\n"]