Disable plugins on Eclipse startup

Try to start eclipse with the -clean option.

Or try to delete move the pluings and the features.

Posting the error-message is more useful than "there was an error". Look into the logfile or try to start from the console and post the error message here.

Edit: Irbull is right. Of course don't delete the files, just move them in another directory so you can move them back. His solution sounds very helpful and is even more professional.

As another person mentioned, you can try the -clean option. However, if it still fails to load and you need to revert your install, you should NOT simply delete a plugin on disk. If Eclipse thinks a plugin is there, and suddenly it's removed, you will run into all sorts of problems in the future.

The best approach is to use the Eclipse director (a managing application) to revert your install (this comes installed with Eclipse). You will need to know what previous revision you would like to revert to. You can see all the previous revisions of your Eclipse install in /p2/org.eclipse.p2.engine/profileRegistry/ where profile name is likely something like SDKProfile. In here you will see a number of profiles. Each one represents a previous state of your Eclipse install. Find the revision you would like to revert to (they should all have a timestamp on them) and from the root of Eclipse execute the following command:

./eclipse -application org.eclipse.equinox.p2.director -revert 1611571876423 -repository https://download.eclipse.org/releases/2020-12

Obviously replace the revision with the one you want to revert too. This says, please revert my Eclipse install to 1611571876423, and if you need any dependencies, look in https://download.eclipse.org/releases/2020-12 (Eclipse 4.18). If you're doing this for a different version of Eclipse, then change the URL as appropriate.