MySQL Workbench 6.3 (Mac) hangs on simple queries

I am using MySQL Workbench 6.3.7 build 1199 CE (64 bits) on a Mac with OS X Yosemite 10.10.5. I am connecting to an Amazon RDS MySQL instance.

When I enter a simple query such as

select * from `devices`;

and click the lightning-bolt-with-cursor icon, the query starts, indicated by the spinner activating next to the "SQL File 4" tab in the following screenshot. However, the query doesn't complete and it just hangs. The white-hand-in-red-stop-sign icon is disabled.

I can only force quit MySQL Workbench from this point on. If I try to do a regular quit, nothing happens.

How can I consistently run a simple query on my database? Sometimes it works (maybe 10% of the time), but it mostly just hangs.

UPDATE 3: The problem is fixed for MacOS HighSierra in MySQL Workbench 6.3.10.

UPDATE 2: It looks like the bug is recurring again in MacOS HighSierra. See https://bugs.mysql.com/bug.php?id=83658 for more details.

There is an unofficial build that fixes the problem. You can download it at: https://drive.google.com/drive/folders/0B2fTesDcrHzVRGVFWEdILWpuaEE?usp=sharing

The build was created by Bob Davenport. See https://bugs.mysql.com/bug.php?id=87714 for more details.

UPDATE: The bug is fixed in MySQL Workbench 6.3.9.

----------------------- original answer -----------------------

It is a known MySQL bug: http://bugs.mysql.com/bug.php?id=83658 caused by GateKeeper Path Randomisation introduced in MacOS Sierra. See https://weblog.rogueamoeba.com/2016/06/29/sierra-and-gatekeeper-path-randomization/.

A possible workaround is to remove the Quarantine ACL:

xattr -dr com.apple.quarantine "/Applications/MySQLWorkbench.app"

I found that if you use the latest 6.3 version, that in order to get queries to work, you have open a first connection and ignore it and then open a second connection. This creates two tabs in the workbench. If you perform your queries in the second tab, it works. If you try in the first tab, it hangs.

I also have found that you have to do a force quit the workbench.

I hope the mysql folks get this fixed.