I restored my old project but when I tried to open Project\Option menu I get an error:
"keytool error: java.io.IOException: Keystore was tampered with, or password was incorect."
I use Delphi XE8 SP1
How to fix it?
I think that you have a corrupted cacerts database keystore or the password that delphi is trying to use is changed for some reason . I'm not quite sure whether the Delphi IDE is working on the main cacerts key store or on its own generated jks file.
Take a look and see if you have some jks files inside your project, if yes try to remove them and see if the Delphi IDE recreate them at the next opening of the project ...
In the case you don't have any jks file try to reinstall the JVM (removing all the folders and files of the old JVM).
From what I can assume here there should be some jks file referenced by the project and maybe the new version of Delphi is trying to access it with a different password, so try to delete the jks and see if Delphi recreate it correctly .
In the worst case you can generate a new project with the new Delphi XE8 installation and import old project source files(Units) ...