If you don't have too many user-modifications of the IDE or additionally installed packages you should reset your user profile: Go to "View" > "IDE Internals" > "About IDE" and find the name of the directory which stores your settings next to the "Primary config directory" entry. Then exit the IDE, go to that directory and rename it (just to have a backup). When you now restart Lazarus again, new default settings will be created, just as if you just had installed Lazarus for the first time. The issue that you report should be gone. There may be an error message, though, about packages not being found - ignore it.
In the new IDE you must first reinstall all your packages that you had used in addition to the built-in packages. Since all your user-settings are list you also must set up Lazarus again as you need it. But do this in steps so that you do not repeat the misconfiguration that lead to the issue reported.