Jesus Vigo reviews 10 documented issues affecting OS X Yosemite and offers troubleshooting tips to work through them.

Apple's Yosemite has been the most ambitious OS X release in unifying
the desktop and iOS mobile devices. Some of the benefits, however, can
only be enjoyed by installing OS X 10.10 and iOS 8 on your respective
devices.
As advancements are made, there are certain concessions if the
technology is to move forward, and sometimes this requires upgrading
older hardware to take advantage of newer features. However, as with any
new product, bugs will be identified that prevent some functions from
working as advertised.
Thankfully, most of the difficulties surrounding Yosemite can be resolved with some troubleshooting and/or software updates. Let's review below 10 of the more common issues affecting Yosemite and how to resolve them.
1. Wi-Fi connectivity
Symptoms: Wireless connection drops connectivity and
goes offline for approx. 30-45 seconds at a time, often at 10-15 minute
intervals between loss of connections.
Causes: The issue usually pertains to a buggy Wi-Fi
driver. Unfortunately, this relies squarely on Apple's shoulders, as the
driver must be updated before a permanent solution may be found.
Sometimes the issue pertains to router and/or specific wireless
settings.
Solution: As of this writing,
the current version of OS X is 10.10.1,
which includes better Wi-Fi reliability. While this has been known to
resolve some issues, many users are still experiencing trouble and
holding out hope for the forthcoming 10.10.2 update.
Additional troubleshooting steps involve reviewing wireless and/or
router settings on your home equipment to verify compatibility and check
for common wireless issues, such as distance, obstacles (i.e., concrete
walls, which are known to impede signals), and interference brought on
by multiple wireless access points concentrated in a general area, since
the 2.4 Ghz band Wi-Fi typically operates on is susceptible to
overcrowding from cordless phones, neighboring routers, and other
gadgets operating on the same frequency.
2. Trouble booting OS X
Symptoms: Mac computer powers on and
initiates the boot process, yet the progress bar fills up about halfway
and then just hangs there for an unspecified amount of time.
Causes: Boot issues are difficult to troubleshoot,
since there are so many variables that can affect the process. You could
be experiencing hardware failure, software extensions gone awry, or a
combination of multiple issues could be keeping your Mac computer from
starting up properly.
Solution: Best practices in troubleshooting are the
best offense to tackling boot issues affecting your Mac. Combined with a
little common sense, boot issues can be resolved relatively quickly and
painlessly.
3. Excessive RAM usage
Symptoms: RAM usage is throttled to its maximum capacity, preventing the use of certain applications or features.
Causes: RAM is used by a computer to keep application
information moving as it transitions from storage to the CPU for
processing and back. Yet, somewhere along the line, a process takes on
more than its share of allocated memory or an app has a memory leak that
causes it to continue to use up RAM until nothing is left for the
system to run stably.
Solution: The quickest way of identifying an offending
application or process is by launching the Activity Monitor.app from the
Applications | Utilities folder. Checking the memory tab will list each
process currently running and the total commit of RAM being used by
each app in descending order from greatest amount used.
Many times, unsuspecting applications are loaded when a user logs on to a
computer, and these apps continue to run, unfettered and often times
needlessly, which negatively impacts memory performance. Quitting these
processes will reallocate the previously used RAM back to the systems
pool of available RAM.
4. Apple Mail trouble
Symptoms: Apple Mail has difficulty sending/receiving
email for previously configured accounts. Also, certain messages can't
be viewed when the message is selected.
Causes: Regarding the former, this is a known issue
that affects Macs upgraded to Yosemite from a previous version of OS X.
Apple Mail seemingly "forgets" email server settings -- typically the
SMTP server settings -- allowing users to only receive email but not
send out. As for the latter, one needs to look at how Mail stores
messages in the .MBOX format. These files, much like their Microsoft
Outlook counterparts, .PST files, become corrupt at times, preventing
the retrieval of stored messages in folders.
Solution: Correcting send/receive errors are as easy as
contacting your email service provider or searching for the
POP/IMAP/SMTP settings on their support page and reconfiguring the
incoming/outgoing server settings for the affected email accounts.
Fixing stored messages in Mail requires a bit more work to resolve. If
you can see the messages listed in Mail but can't access them, click on
the folder that contains the affected messages and select Mailbox |
Export Mailbox... from the menu bar. A window will open, prompting you
to select a location to backup the file. Click choose, and the messages
will be backed to the selected location, including folder hierarchy.
Once the files have been backed up, delete the folders from Apple Mail
and import the newly created .MBOX folder by selecting File | Import
Mailboxes... and selecting the back-up file to import.
5. Handoff prompts after disconnecting phone call
Symptoms: Handoff prompts you to answer an incoming
phone call from your iPhone, and after disconnecting or ending the call,
OS X continues to prompt you and does not allow you to end the call.
Causes: The exact cause of this phenomenon isn't
exactly known -- it can be attributed to OS X, iOS, or Wi-Fi/Bluetooth
that's used for connectivity.
Solution: Typically,
Continuity-related
issues are fleeting. Simply re-establishing a Wi-Fi/Bluetooth
connection by powering them off temporarily and restarting them resolves
the hiccup. An additional step would involve rebooting OS X and iOS,
which causes the devices and connection protocols to resynchronize with
each other.
6. AirDrop between iOS/OS X
Symptoms: AirDrop service not detected between OS X and iOS, preventing data transfer.
Causes: AirDrop can be a little finicky between iOS and
OS X. The majority of the disconnection occurs when the feature is used
on unsupported hardware.
Solution: Verify that both your
Mac and iOS device meet the minimum requirements
for cross-AirDrop support. Once that's done, check to make sure AirDrop
is enabled on both OS X/iOS devices and that both devices have Wi-Fi
and Bluetooth enabled. If AirDrop is still not communicating, try these
troubleshooting steps to mitigate the issue.
7. App-specific issues
Symptoms: Applications not working as advertised or certain features/functions are disabled.
Causes: Changes in OS X, particularly with all the new
API additions for developers to utilize when coding their applications,
bring a host of random issues when it comes to app compatibility.
Solution: Most of the time, developers have time to
sort out any bugs that present themselves by the time an OS is ready for
public release. However, as stated before, some issues are unforeseen
and require updates or patches to correct. The best practice is to
ensure that OS X is fully updated, plus any applications that might be
experiencing trouble with Yosemite. Checking the vendors' support pages
will often yield download links for updated versions of software or
patches and workarounds for known issues affecting users.
8. Battery life
Symptoms: Battery life is drastically reduced when
compared to its current use with Yosemite and the previously installed
version of OS X on your Apple laptop.
Causes: Any potential hardware defects aside, such as
malfunctioning cells in the battery themselves, changes in battery life
for typical usage is usually a direct result of a driver issue within
the OS itself and/or the use of software that may not be optimized for
Yosemite.
Solution: Similar to issue #7 above, ensure that your
MacBook is using the latest version of OS X 10.10.x and that all
software applications are also updated to their latest versions, since
this code typically has been optimized for use with the latest version
of OS X.
An excellent technique that one could use to deduce any offending apps
is located in the Energy tab of the Activity Monitor.app in Yosemite. A
listing will be presented of all the applications currently running on
your device, along with the Energy Impact -- updated in real time -- and
the average Energy Impact as determined by use over a period of time.
Additionally, with certain apps, like Safari for example, plugins are
also included by selecting the arrow to expand and display such services
and their respective impact on your systems power consumption.
Any outstanding offenders displayed here might be unknown to the
software developers, and you may be able to submit a bug report on the
developer's website explaining the problem so that they can issue a
patch or rework the code in a future update.
9. Lag brought on by Spotlight indexing
Symptoms: Yosemite may, at certain times, become extremely slow and lag while you're trying to work on the computer.
Causes: Spotlight -- Apple's system-wide search
function -- must index data located on your computer in order to be able
to report lightning-fast searches. This indexing builds a catalog of
all the data on your device. Depending on the amount of data, completion
of this process may take some time, which will impact the resources on
your computer while it's building the index.
Solution: If Spotlight is not used and you wish to turn the service off, it can be done so by executing the following command in Terminal:
sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist
However, since Spotlight is a useful piece of technology, you may wish
to keep it enabled and just limit what is indexed. To do so, launch
System Preferences | Spotlight and select the Search Results tab. There,
you'll find a number of search categories. Uncheck the selections you
wish to exclude from indexing, and they'll be removed immediately.
Similarly, if there are specific files or folders you wish to exclude,
or even a particular drive, click the Privacy tab and use the plus sign
[+] to add paths you wish to have excluded from Spotlight. All paths
added will immediately be excluded from indexing and removed from the
index catalog to keep Spotlight optimized.
10. Upgrade vs. clean installation
Symptoms: Prior to installing Yosemite (and perhaps
given the number of issues affecting this latest version of OS X), users
must decide how they wish to install the newest OS to maximize the
operating system potential and minimize any possible issues.
Causes: Installing the latest version of OS X offers
two paths: Upgrade and Clean Install. Which one you choose will depend
on your specific needs, available storage space, and whether data has
been backed up.
Solution: Upgrading is the easiest solution and the one
most will choose. It allows end-users to keep their data, apps, and
settings in place while replacing the previous OS with Yosemite.
The downside to upgrading is that any issues that existed with OS X
previously will continue to plague the system after upgrading to
Yosemite. Also, possible incompatibilities with apps or corrupt files
might be enough to destabilize OS X Yosemite, and it may lead to some of
the known bugs users have been experiencing.
Clean installs effectively format the HDD/SSD and installs a fresh copy
of Yosemite on your Mac. During the format process, all data is lost --
as are settings, preferences, and pretty much everything else. But once
the process is complete, you have a brand new installation of your OS,
and none of the previously installed apps or settings will be there to
conflict with OS X.
The main caveat to clean installs is data loss. This isn't much of a
problem for users who practice regular backups of their data. However,
it will be an issue for users who haven't backed up, since they'll have
to first backup any data they don't want to lose, which adds
considerable time to the overall process. Any settings will also be
lost, passwords remembered, email configurations, etc. You'll basically
be starting from scratch, which might be a deal breaker if you use your
Mac for work or critical functions.
I personally advocate for a clean install, since the payoff of having a
sanitized system far outweighs any time it will take to reconfigure
certain apps or settings. Plus, since my data is regularly backed up,
it's easy to restore my files once my clean copy of OS X is ready for
use. However, I do recognize that it's less than ideal for some
solutions, so tread lightly and consider benefits vs. time before
making the decision either way.
Lastly, troubleshooting is going to be essential with any OS -- Apple,
Microsoft, or Linux. Things happen, updates may fix one problem only to
open another issue somewhere else. Such is the way of computers and code
generated by humans -- they are both prone to occasional error. The
silver lining is that it keeps IT working and certainly never makes for a
dull moment.
What other troubleshooting tips would you recommend for OS X Yosemite? Share your experience in the discussion thread below.
~ Jesus Vigo