Having installed Apache Flex SDK 4.16.0, I open Flash Builder 4.7 to see this error dialog message:
An error has occurred.
See the log file at <dir>/.log.
The .log in question is 1676 lines long, starts like this:
!SESSION 2017-09-20 10:59:34.184 -----------------------------------------------
eclipse.buildId=M20110909-1335
java.version=1.8.0_144
java.vendor=Oracle Corporation
BootLoader constants: OS=macosx, ARCH=x86_64, WS=cocoa, NL=en_US
Framework arguments: -keyring /Users/<REDACTED>/.eclipse_keyring -showlocation
Command-line arguments: -os macosx -ws cocoa -arch x86_64 -keyring /Users/<REDACTED>/.eclipse_keyring -consoleLog -showlocation
!ENTRY org.eclipse.core.net 1 0 2017-09-20 10:59:42.241
!MESSAGE System property http.nonProxyHosts has been set to local|*.local|169.254/16|*.169.254/16 by an external source. This value will be overwritten using the values from the preferences
!ENTRY org.eclipse.osgi 4 0 2017-09-20 10:59:42.867
!MESSAGE An error occurred while automatically activating bundle com.adobe.flexbuilder.project (68).
!STACK 0
org.osgi.framework.BundleException: Exception in com.adobe.flexbuilder.project.internal.FlexProjectCore.start() of bundle com.adobe.flexbuilder.project.
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:734)
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:683)
at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:381)
and ends like this:
at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:702)
... 149 more
!ENTRY org.eclipse.core.jobs 2 2 2017-09-20 10:59:43.401
!MESSAGE Job found still running after platform shutdown. Jobs should be canceled by the plugin that scheduled them during shutdown: org.eclipse.ui.internal.ide.IDEWorkbenchActivityHelper$4
My set up is:
OS: Sierra 10.12.6
Hardware: MBP Retina, 15-inch, Mid 2015
Processor: 2.2 GHz Intel Core i7
Memory: 16 GB 1600 MHz DDR3
Graphics: Intel Iris Pro 1536 MB
I not proficient with Eclipse or Java^ and therefore do not know what else I can tell you. Any help gratefully received, thank you.
^ I am Swift (now) and ActionScript (formerly) programmer
You might want to try a new or empty Workspace to see if that works.
There are some tips on running Running Adobe Flash Builder on Win and Mac with Java 7/8
You may also want to increase the Java virtual memory settings if you haven't done so already.