Several people on the Xojo forums have complained about Xojo crashing on them multiple times per day. I rarely, if ever, have that issue but I do occasionally get an issue where a compiled application will do something that’s batsh*t crazy and nonsensical.
For example, I had some database code that was doing a simple database query where the error bit was returning true (or at least the compiled application was saying so). I spent hours trying to figure out why it was returning an error. I replaced the database file (SQLite) with a fresh file, ran the query in external editors, I did practically everything and finally I gave up. I shutdown Xojo and restarted my iMac. The issue persisted.
Finally I did my fixit option of last choice: I cleared my plugin cache. I restarted Xojo and voila! The problem went away.
This happens once or twice a year for me. We use a lot of plugins from Monkeybread and Einhugur (and others too) and switch versions of Xojo quite a bit so I’m never really surprised that this happens. Usually when I clear the cache there are a LOT of versions listed.
The Xojo IDE has plugins that it has to compile and use so those that don’t use third-party plugins may also experience this issue. And of course the project cache is true for everyone as well.
For those using third-party plugins, it’s ALWAYS a good idea to keep up to date. I know Monkeybread Software has done a LOT of work recently getting ready for 64-bit for Windows and Einhugur has done a lot of work recently to support Gtk3 in Linux and 64-bit Windows. I know I’m still waiting on the Einhugur Treeview plugin so I can move a Linux project from 2017 R1.1 to something newer. Before complaining to Xojo do your due diligence and check for newer versions!
So my advice is when things are acting weird, empty the plugin and project caches. On macSO this is in ~user/Library/Caches/Xojo. In Windows this at C:\Users\YOUR USERNAME\AppData\Local\Temp\ with two folders, XojoIDEPlugins, and Xojo scratch XXXX folder with XXXX being some specific number (build number?). I have no idea for Linux (sorry).
This might not be a perfect solution but it might keep you from going crazy(er).