I have had similar issue when the shortcuts become corrupt either because someone deleted what a shortcut was pointing at or it simply had issue for no reason.  In my case I usually got an error though that kicked me out of Sage.  The fix was to delete the shortcut and recreate it.  In my experience when Sage appears to "lock" it is not actually locked rather the screen trying to open has lost focus and is opening on a monitor that does not exist or off the screen.   There is a Sage KB on resetting the positions of screens within the program if you think that may be the issue.  I can find it if you do not.  Thanks

Completely forgot to mention that I also did re-create the shortcuts and the error persists.  Thank you for trying to help.  I will look for the article, I think I know what you are referring to where it cascades all your windows??

This one is a bit different.  The windows are not cascaded they are simply gone and not capable of being brought back sometimes.  Here are two articles below.   I have found that, especially in remote desktop environments, you cannot move any Sage related screens off the main monitor.   If you do they will eventually "disappear" and make it seem like you are locked.  I advise everyone at my place to keep all Sage related reports, tasks, and screens on the monitor that is marked as Main within Windows.  it is tougher to fix a reg entry issue on a remote desktop server but the second article is profile related and easier to do in that circumstance.

https://support.na.sage.com/selfservice/viewdocument.do?noCount=true&externalId=68981&sliceId=1&isLoadPublishedVer=&docType=kc&docTypeID=DT_Article&stateId=1756&cmd=displayKC&dialogID=65262&ViewedDocsListHelper=com.kanisa.apps.common.BaseViewedDocsListHelperImpl&openedFromSearchResults=true

https://support.na.sage.com/selfservice/viewdocument.do?noCount=true&externalId=18314&sliceId=1&isLoadPublishedVer=&docType=kc&docTypeID=DT_Article&stateId=1756&cmd=displayKC&dialogID=65262&ViewedDocsListHelper=com.kanisa.apps.common.BaseViewedDocsListHelperImpl&openedFromSearchResults=true

I have had success with using this trick to get remote desktop items that open off-screen to come back to the main screen. We host our servers in the cloud so Sage is always remote for us.

Of course, this trick only works if you can see the icon at the bottom of your screen showing it's open but you just can't see it.

My situations never seem to fall into that.  We can never see the task bar icon.  I know I never have an issue with anyone as long as they keep their Sage items on the main screen.  This includes Paperless as well. 

Thanks Jeff.  I tried the option in your first link and it didn't work.  The second link is refering to My Tasks and I don't even know what that's talking about?  I have Applications and Favorites, I don't see aynthing called Tasks or My Tasks... So I have a shortcut in Favorites to AP Invoices Inquiry.  And I click it and nothing seems to happen. I then go back to the Desktop application and I get the little bling error sound and cannot see the icon at the bottom of the screen (as kaysong70 had suggested).  I just think this is truly odd because I have used this shortcut a million times and never had this issue.  It happens with a few other shortcuts as well, but not all of them. And doesn't seem to matter if I recreate them, still happens.  

Also I use two screens (and have for years).  I guess I will try the "main screen" option you suggested (but for the record, if that fixes it, how ridiculous!!)

OK so I just closed out again and when I did I got TS 6214 Invalid Window Columns error.  I looked that up in the Knowledgebase and found ID 24636.  I followed that (which was essentially the same directions, but this time I renamed all of the Timeberline directory instead of just AP and AR).  I also set up my "main" and opened Sage in the "main" screen as suggested.  I then logged back in and tried to run the AP Invoices Inquiry from my Favorites menu and it worked.  Hard to know if it was the renaming the REG EDIT or doing everything in one screen, so that may be trial and error while I figure that out.  But, the point is, I'm back in business.  Sorry there's no clear answer for others who come across this but at least there are several options to try.

Thank you @Jeff Rudacille and @kaysong for your help!

Glad you are back in business!

Glad you are back in business.  The suggestion to keep all Sage screens on the main monitor was actually not a troubleshooting find it is in one of their KB's or it used to be.  I found that when we followed it the issues went away.   I have also found that moving Sage to the "main screen" after you lose screens does no good.  You have to get rid of the files or keys controlling the screen location then keep Sage on the main screen going forward.