Incompatibilities between Eclipse 4.20 and 4.21

Eclipse changed in incompatible ways between 4.20 and 4.21 in ways that affect plug-ins. The following entries describe the areas that changed and provide instructions for migrating 4.20 plug-ins to 4.21. Note that you only need to look here if you are experiencing problems running your 4.20 plug-in on 4.21.

See also the list of deprecated API removals for this release.