This is the second bug fix release to continue to address the problems found in version 21.05.01 after release, but there are a few low risk additions:

Added Speed parameter to the Timer video filter.
Added keyboard shortcuts to switch between the stock layouts: <kbd>Alt</kbd>+<kbd>1</kbd> through <kbd>6</kbd>.
Added Import button to Playlist. (Thanks, @hbtalha!)
Added an Apply button next to Properties > Speed to improve workflow when using mouse wheel.

New Bugs (in version 21.05.01/18)

Fixed playback may hang when playing different Playlist items.
Fixed alpha presets in Export.
Fixed a possible crash when changing Settings > Preview Scaling.
Fixed a possible crash when using Crop: Source and Size, Position & Rotate filters on the same clip.
Fixed Size, Position & Rotate filters not reloading.
Fixed reloading Keyframes for a filter on Output.
Fixed changing Properties > Color Range for a clip in the Source player.
Fixed playhead moves to the beginning of the Timeline when dragging an image from Source.
Fixed a proxy may used instead of the original when dropping from file manager to Timeline.
Fixed Fade In/Out on Timeline may add filters in wrong order.
Fixed a crash trying to make thumbnail for an invalid playlist item when loading a project.
Fixed Playlist > Play After Open not working.
Fixed missing proxies not generated for an opened project when Settings > Proxy > Use Proxy turned on.
Fixed File > Export EDL creates empty file.

Old Bugs

Fixed Center bias in Crop: Source filter.
Fixed a crash using Mask: From File and Size, Position & Rotate filters on the same color clip.
Fixed the Export > H.264 High Profile preset was producing main profile on NVIDIA.
Fixed a crash when using Paste after a File > Close or File > New.
Fixed a Project name with a slash is accepted but fails.
Fixed a possible crash when changing Settings > Theme.
Fixed Mask: Simple Shape moves when deleting all keyframes: no longer allowed to delete the last keyframe; use the keyframe toggle button in the parameters area of Filters.
Fixed maintaining the image center when reset Size, Position & Rotate > Zoom.
Improved using the mouse wheel to zoom in Size, Position & Rotate filter.
Improved the range of the new Zoom keyframe values when keyframes are changed or removed.
Fixed custom Export preset may load with incorrect frame rate.
Fixed Playlist > Replace may replaced with timeline and appear as <tractor> and cause a crash if the Project player it active.
Fixed inconsistent handling of keyframes when splitting a trimming a clip.
Fixed high CPU usage and a long wait after multiple Stabilize analysis jobs.
Fixed a crash when a Stabilize analysis (.stab) file fails to open.
Fixed a crash when Stabilize > Accuracy is 9 or higher.
Fixed remembering the last-opened folder when choosing Properties > Video > Custom... for a transition with video filter Mask: From File > File > Custom....