I've recently been trying out Unity( Under windows 10 ) and its a wonderful tool.  However, I recently updated Unity to a new version, and since then my current project - created in a slightly earlier version - is now crashing.

So going back to  the beginning, I select my project to load, and after selection I get a message that boils down to this...

"The saved project does not match the launched editor"

"This may require re-import.  Please be aware that opening in an older version is unsupported."

...which gives me the option to continue or quit.  So, solidering on, I continue.  Which is then strange because I always get a "hold on" message saying "compiling scripts" which appears for a short while and the disappears.  However, upon trying to click on anything in the interface the message will reappear and the same thing happens. From there the only option is to "close window" on the program to exit it.

Looking into it, there was the suggestion to "re-import all" in the assets menu, but alas the crashes still happen.  Another suggestion is that Visual Studio doesn't play well with Unity, although I find that hard to believe.  That said, it would explain the "compiling scripts" part.  The timing of this behaviour does happen, but sometimes its upon loading the project, others its after running the project and switching between Unity and Visual Studio for the scripts.

At this point I'm thinking "Well, if Unity is going to crash like this after doing a quick update then what other issues should one expect to encounter further down the road?", but logically I'm keeping in mind that Unity is an industry standard tool that is depended upon by studios...and that its most likely just me overlooking something.

Any suggestions or thoughts are welcome.

Cheers.

Steve.

Check unity's logfile, since it may include an explanation of what was happening which caused or was related to the crash.  If you're on Windows, it's at:

C:\Users\<username>\AppData\Local\Unity\Editor\Editor.log

You can try deleting your Temp and Library folders.  They contain files that Unity can regenerate from your Assets folder.  Sometimes Temp or Library can become corrupt.  The Temp folder is normally deleted when Unity exits cleanly, so if Unity crashes it can sometimes leave it behind.  Deleting the Temp folder is always safe after Unity crashes.  The Library folder can take a long time to regenerate based on the number and complexity of your Assets.

During Unity upgrades, frequently some of the Unity C# API methods will be obsolete/renamed.  Unity tries to automatically replace these before the "compiling scripts" phase.  It can't always get everything.  You can try temporarily removing some of your scripts from the project to see if you can get it to finish compiling.  Same goes for DLL files.

Visual Studio works fine with all versions of Unity that I've used (from 3.x through 2018.x so far)

Nypyren, that has at least given me something to consider and try. 

Cheers!

Sounds like you are using a project that includes Editor specific code that dosen't play very well with a newer Unity version. This may be because Unity depricated some functions and/or replaced how certain functions work. This is the most occuring cause of issues when migrating from an older Unity version.

Unity meanwhile does a little bit of self healing trying to replace old/depricated function calls in the code base to newer API functions if possible but the problem will stay the same. You may have some Assets or Plugins that don't play very well with the newer version

Just a quick update as the problem now seems to have been solved, but I'm going to give it another 48 hours of testing before I edit this thread as solved...

Basically, the project was not being saved when I assumed it had been.  The error message "The saved project does not match the launched editor" was persisting even though I had saved the project previously and then reloaded it.  So, before the crash kicked in, I altered a minor option which was the colour of a cube and then saved it. I assume that by making a small edit that Unity then allows the project to be saved...

I have put back all the C# scripts that were deleted before and it now seems to be working fine.  Visual Studio works as expected too.

Don't try to mark discussions as "solved".  This is a discussion board, not a Q&A board. We remove those markers when people add them because it halts discussion, and other people may have more to contribute.

Something to keep in mind, if you are fine with last years(ish) feature set, you can use the Unity LTS release (https://unity3d.com/unity/qa/lts-releases) for your "long term" projects.   It only gets bug fixes, and stays feature stable and is supported for a much longer cycle than their regular updates.

I would also venture to guess that upgrading between major LTS versions is probably a little more tested..

Additionally, I would recommend reading the release notes before you run an upgrade, they give you a pretty good heads up on what code they have changed and you can usually spot things that might cause you problems.

2 hours ago, frob said:

Don't try to mark discussions as "solved".  This is a discussion board, not a Q&A board. We remove those markers when people add them because it halts discussion, and other people may have more to contribute.

Ah, okay then.

Thanks Frob.

Its been a few days now and so far crash-free!

Thank you all for the help and your time.

Cheers.

Steve.