I should probably start out technical posts going “Your Mileage May Vary” but the more times I did this the less worried I got about writing this post.
Anyway – It’s time for upgrades if you’re doing anything in QGIS land. Especially if you’re running a Long Term Release. QGIS 3.10 has had enough patches you should start using it. A client called with a problem in QGIS and I said “WELL LETS UPGRADE!!!!”. She did. QGIS Started crashing. QGIS wouldn’t save. Nothing good was happening. Of course I feel extra great about it all because I said “UPGRADE THERE IS NOTHING THAT CAN GO WRONG”.
All is not lost though. It’s actually pretty easy trouble shooting the problem.
QGIS has profiles. What’s a Profile? I’m glad you asked and I’ll refer you to the awesome documentation. In short – anytime you start QGIS you’re reading your default profile and that holds everything from variables/models/connections as well as plugins. Do I use profiles? Yes for the QGIS class because I want everything to be just like I installed it BUT I don’t want to loose anything I’m working on (So I’ll have a Training Profile and a default profile). Yes – Gone are the days where I’d gleefully just reset my install by deleting my profile.
If you start QGIS you can go to Settings -> User Profiles -> Open Active Profile Folder and all the details appear. Plus you get to see where this directory lives on your computer.
So how did we fix it? You upgraded and nothing is going right OR just some random QGIS weirdness happening. Make a new profile. I’m going to make one called “blog” by going to Settings -> User Profiles -> New Profile.
Guess what – A new folder appears along side the default (if you happen to be watching the directory where all this is stored).
You’ll also notice you’ve got a brand new session of QGIS that will open up. That brand new session will have none of your settings. WHAT? Yeah – you’re running a brand new “fresh” session of QGIS so you have no settings. No Database connections. No Plugins. Enjoy the untouched landscape of QGIS.
What happened with the client? I had them make a new profile and load their existing QGZ file using that new profile and it worked. Why? No idea. Maybe a plugin wasn’t happy. Maybe “some weird computer thing” happened. What I think happened – and this is pure speculation on my end: They were running 3.4 LTR and had been negligent in installing the patches that are issued once a month. So their copy of 3.4 was pretty old plus they hadn’t upgraded plugins……and then suddenly we jump to 3.10. If I were sitting there I probably would have upgraded plugins and maybe installed the last release of 3.4 before trying the 3.10 release. I’m weird that way and that’s not complaining about QGIS’s installation process. Things happen.
How do I make it even easier. Close QGIS. Rename the default profile folder to default-old. I rename the blog profile to default. Copy the QGIS folder, bookmarks.xml, qgis.db, qgis-auth.db, and symbology-style.db over to the new default profile out of the old one. Usually I just re-download the plugins. If I have QGIS models I’ve made I will move the processing folder over.
Do I use this “one neat trick” a lot? Not really…BUT if you ever get to a point where QGIS is crashing or not starting right make a new profile and see if that straightens things out. At the end of the day I have three profiles:
The one thing I enjoy with the profiles: If something is really being weird on the client’s end I can have them zip their profile up and dropbox/email it to me. I can use it and then pick at it a bit and come up with an answer. I can pull someone else’s QGIS session into mine and trouble shoot some problems they have. How often do I use that? Not often…BUT when you need it you really need it.
So – QGIS Profiles. Read the Docs! Make a test profile “just because”.
Stay safe out there.