In Delphi 10.1, without all the latest updates, if you get Delphi startup crashes, you can get around them in some cases, by removing optional parts of Delphi that are taking delphi down. One such piece I usually rename so that it can't get re-enabled again, is the community toolbar IDE plugin bpl,
I go into the Program Files (x86), folder, then Embarcadero\Studio\18.0\bin, then rename CommunityToolbar240.bpl, by putting a tilde (~) on the front of the name.
Not only does Delphi 10.1 berlin RTM actually start up without access violations and crashes, an unsightly and useless toolbar is gone from the IDE. I consider that win-win.
I believe the above issue must have been fixed in Update 1 or Update 2. But given with how much of a pain installing so called updates that are really not updates but full reinstalls is you can't really blame me, can you? I work in a variety of VMs and it's not a one time reinstall for me, but a series of VMs with a series of Delphi versions in each. I have had crashes in the community toolbar ever since whatever version it was first introduced in, and it remains one of the ugliest and most pointless IDE plugins ever.
There are other IDE plugin bits which are optional in Delphi, and if you're having a startup crash, one of the other things i sometimes have tried disabling is the debugger plugins for the C++ builder (if you have the full "RAD Studio" SKU, you have both), and a few other things which have historically been bad.
If you're running out of memory or you find the IDE is slow, it's also helpful to remove bits that might be causing that, and see if the problem goes away, even if only as a technique to find and isolate, and kindly report your findings in the Quality Portal.
If renaming the dll/bpl doesn't make things better, you can always change your environment back to its original state, by putting it back to its original name.
I also find that if my registry settings are to blame, renaming the current-user embarcadero BDS registry hive to "BDS_old" and then starting with a fresh settings, and see if the crash/problem goes away is also a helpful step in bisecting and understanding bad Delphi IDE states. Clearly the rename is going to nuke all your local configuration settings and get you back to install-time defaults. If your environment is self contained and easily set up again by just running some package-install and library-path setup tool, this technique can be doubly useful.