The issue is related to the Google Plus theme, seems like you have deleted the theme manually from the server, but there's a remainder in the database of that theme. Go to ow_base_theme table locate google plus row and delete it

Thank you for the help.  I am a newbie to oxwall, unfortunately, and I have looked everywhere for the ow_base_theme table and have not been able to locate it.  I had restored my website, although any new updates produce the same results until I locate this and delete it.  Any guidance you can give will be very much appreciated.  Thank you,

Do you have Google Plus theme in ow_themes folder on your server?

If not, upload it, enable dev mode and refresh your website, see if the issue persists, then disable dev mode. 

I do have it.  It was never deleted.  It still shows up in my admin themes area.  Which is why I was a bit confused why this just started happening.

Yes.  I just checked again to make sure.  The folder for google plus is there.

So lesson learned.  I was able to get my site back up and running by installing a back up, although the backup was 24 hours old.  That does not seem too bad, except that I have a very active site, so that was a lot of user data lost.  Even though I was just updating a plugin that I already had installed, I should not have taken that for granted and backed up anyway.

With that said, I still am unable to update any plugin at the moment due to the above error I am getting.  I am not able to figure out how to fix that error.  Does anyone have any suggestions for me.  I would try to delete the code that was suggested above, although I am still fairly new to oxwall and have not been able to locate it.  As far as the theme that the error is referring to, I still have it in both my cpanel and my admin area and never deleted it, so I really do not know what has caused this error.  There are some plugins I have that are in desperate need of updating, and I would like to update oxwall as well(same thing happens when I try updating oxwall, fyi).  So any suggestions would be greatly appreciated.  Thank you in advance.

Swinginpdx, as you have access now to the Google plus theme, can you please delete it completely via Admin Panel and try to update the software and plugins, let us know if the issue persists. Seems like something is wrong with the theme, let's check it 

so that did not work.  It gave me a 500 error when I tried to delete it through my oxwall admin area.  I hit refresh and the error went away and it said theme deleted, although there is a blank space where the theme was.  When I highlight the blank space, it shows all of the info of the theme and gives option to delete or activate.  I tried deleting again and the same thing happened.  I refreshed my site through dev mode and tried again and same results.  I tried to re-upload and refresh like you stated previously and nothing changed.  Still blank space and still wont delete.  I activated and the theme does not apply at all.  It just created a text based site.  I have the theme in "oxwall Themes" folder still.  I even went and re-downloaded the theme from my purchases and tried the same things again of re-uploading, refreshing and then deleting.  So far, nothing changes and I still get the error when updating the plugin

I am really at a loss here.

Can you please PM me your admin and Cpanel access details, I'll take a look at the issue?

Thank you to Ross for trying to help out.  It looks like he got very busy and just when we were getting to the meat of the problem, we lost contact.  I really need to figure this out because I have a ton of updates to do and I am afraid of losing everything if I do something wrong.  Any help with the error and how to fix it would be greatly appreciated.

Once again, thank you to Ross.  If you happen to see this and have a moment to pick up where we left off, that would be awesome.  If not, I completely understand and appreciate what you tried so far.

Swinginpdx, your core is still 1.7.3 you cannot update your plugins unless you update the platform first. Of course you will get different errors as the plugins update compatible with the higher version of the software. Update your platform then plugins, See this topic: http://www.oxwall.org/forum/topic/24134

Ross, I am not able to upgrade the core.  I get the same error as I do with updateing the plugins.  This actually started when the core was still on 1.7.3.  I lost everything when I tried to update both the core and the plugins(seperately of course).  If you start with the error at the top that we were fist discussing, it does not matter what I try to upgrade, it gives me the white screen and is only able to be fixed if I reload a back up, which just resets my website, it does not actually fix the problem.  That is why I am currently stuck.

Do you have a backup of your website? If yes, I can try to do the update for you, if it is ok and check the issue

So I tried going step by step one more time to do a site upgrade.  I backed up, disabled all plugins, set debug mode to true and then performed the upgrade through softoculus.  As soon as the upgrade finished, I got this error again.  Somewhere there is a conflict with the GooglePlus theme.  I tried removing it through the admin panel as earlier suggested and that did not work.  I still have my site down.  I figured I would wait to see if there is anyone who knows how I can fix this since my members were expecting my site to go down for maintenance today anyway.  If there is anyone who has a suggestion while I have this down, that would be awesome.  Otherwise, I will restore my backup and try this another day.  Thanks in advance.

Oops...forgot the error log:

Error details:Type:ExceptionMessage:Can't find theme dir for `GooglePlus`!File:/home/opennort/public_html/oxwall/ow_system_plugins/base/bol/theme_service.phpLine:326Trace:#0 /home/opennort/public_html/oxwall/ow_system_plugins/base/bol/theme_service.php(309): BOL_ThemeService->processTheme(981) #1 /home/opennort/public_html/oxwall/ow_core/application.php(790): BOL_ThemeService->processAllThemes() #2 /home/opennort/public_html/oxwall/ow_core/application.php(572): OW_Application->updateCachedEntities(1) #3 /home/opennort/public_html/oxwall/ow_core/application.php(161): OW_Application->devActions() #4 /home/opennort/public_html/oxwall/index.php(54): OW_Application->init() #5 {main}

Please PM me your CPanel access details and admin website access details, I'll be happy to do the update for you. 

Before doing that, please make a backup, disable all 3rd party plugins, switch to the default theme. 

Before doing this, can you tell me approximately when you will be able to do this?  My website is very active and even an hour after a backup, there is a lot of information that is added to the site.  If we can set a time up that is good for both of us, that would be best.  I am not at all trying to be difficult, I just know what had been happening when an update takes place and I do not want a ton of information...including new members joining which happens at a rate of about 1-2 an hour...being lost.