I have already sent this to Flightbeam for their support team to figure out. However, I want to see if anyone here will be quicker and has experienced the same issue. I cannot, for the life of me, get the Flightbeam Manager to open without getting the following error message: http://prntscr.com/115flhe 

This is the message that is in the log on the message box:

System.Security.Cryptography.CryptographicException: Key not valid for use in specified state.

   at System.Security.Cryptography.ProtectedData.Unprotect(Byte[] encryptedData, Byte[] optionalEntropy, DataProtectionScope scope)
   at ‎‍‍‮‍‏‎‭‫‫‫‬‬‮‏‫‬‏‭‬‍‪‮.‭‌‏‌‫‎‪‌‌‭‬‫‏‪‪‭‮‬‏‍‭‫‮‪‏‬‌‌‏‭‫‮(String )
   at vLB~\.F$="k6:\,1d%>W:saQW;(.k F$Y\\\\(I\[nq0~6-M`flh}5S$.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at G{Y/0J:0KwSCAa~^ L-\\V|BM.\&$}="j#'!zMk_6q\\$$m#)\,DP'.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<>c.<ThrowAsync>b__6_0(Object state)

It worked for a time before, and all has been well. However, now I am having this issue and do not know how to take care of it without doing harm to my computer. I have uninstalled all the Sceneries that I have associated with them, deleted the files associated with it, including the Manager. Then I did a clean reinstall of all of this, and still have the same issues. I also added an exception to my Windows Firewall, and that did nothing as well. Can someone please help? Running Windows 10 with Lockheed Martin Prepar3D Version 4.5 and 5.1.

Edited April 6, 20215 yr by PilotJY
More Information to add.

Sadly in my opinion Flightbeam have gone over the top with drm and forcing you to log in ect... and when something goes to pot well "ooops" you're on your own. Flightbeam is on my list to never touch again, Active Sky is a close second at this point.

@PilotJY, has it been long since you asked Flightbeam?  Just curious because you're not saying you're being ignored by Flightbeam.  Anyway, try clearing your browser cookies.  Don't know if this will fix this, but I see it listed as a potential solution for this type of error.  

1 hour ago, David Vega said:

@PilotJY, has it been long since you asked Flightbeam?  Just curious because you're not saying you're being ignored by Flightbeam.  Anyway, try clearing your browser cookies.  Don't know if this will fix this, but I see it listed as a potential solution for this type of error.  

Found this post from September 2020. Lars did answered his question. It looks like he still getting that error. To me it looks like something has gone wrong with his windows installation or it got corrupted with a windows update.

Edited April 6, 20215 yr by Samaritano

2 hours ago, Samaritano said:

Found this post from September 2020. Lars did answered his question. It looks like he still getting that error. To me it looks like something has gone wrong with his windows installation or it got corrupted with a windows update.

Thank you for reminding me about that. Thought it was a whole other issue. Apparently it is not. I do not actually remember asking that before. Either way, that fixed it.