The unexpected bug could be removed after some tinkering. Let's keep our fingers crossed that the new bond drawing mechanism is now working.

due to a unexpected bug the app had to be reverted to a state of version 2.9.2

- the rendering of double and other bonds has been tweeked - different bug fixes

- new requested feature added: you can now change the default padding between bonds and atomic symbols in preferences. It is also possible to manually define the padding around individual atomic symbols - bugs related to the display and clipping or cropping of bonds have been fixed - different bug fixes

- new requested feature added: when typing chemical formulas in text fields indices and charges are automatically formated as sub- or superscript. This formula text mode can be switched off in the toolbar - different bug fixes

- new feature added: you can now mirror parts of a molecule in respect to a selected bond - a bug introduced with the last version that duplicated atoms when added indivdually has been fixed - different bug fixes

- the representation of double and triple bonds has been improved. Double bonds follow now the IUPAC recomondations 2008 for graphical representations of chemical structures - bond line insets can now be manually set in the bond section of the attributes popover (advanced settings) - the old drawing mode for double and triple bond can be switched on or off in preferences for compatibility reasons - when hovering over an atom or bond with the mouse, highlighted objects can now be directly deleted when hitting the delete key - different bug fixes

- export errors which led to incorrectly croped bonds have been fixed - multiple MoleculeSketch files can now be exported at once with a new menu command - all types of double bonds can now be accessed with the new double bond button - different bug fixes

- templates for six and five membered rings in Haworth projection have been added - the width of stereo bonds can now be adjusted. If you still wish to use the former style choose the option "calculated" in the attributes or preference panel - an incorretly named nucleic acid was renamed (thank you for pointing it out!) - several bug fixes

- you can now draw rectangles - you can now add a fill color to circles and rectangles - fixed an issue when drawing chains and changing atoms in the chain - small bug fixes

- an issue that misplaced hydrogen atoms when exporting as SVG file has been removed - a pesky bug that changed sub- and superscript text when editing text boxes has been removed - fixed an issue that prevented files from opening when certain programs were installed - A new file extension type ".moleculesketch" was added for compatibility reasons - other small bug fixes

Keyboard shortcuts added: - change the selected element by typing the corresponding letter on the keyboard - change bond type by typing 1 (single bond), 2 (double bond), 3 (triple bond) etc. - when you hover over an atom with the mouse, you can now change the atom symbol by typing - change tools with keyboard shortcuts more information in the what's new section. Otherwise different small bug fixes.

> MoleculeSketch supports again older macOS versions with a minimum of macOS 10.15 with a reduced feature set. For full feature set macOS 14 Sonoma or newer is needed > the color of all selected objects can now be changed at once in the selection popover > in preferences you can now define if a new document should always be opened on app launch > the illustration of double bonds has been improved > several bug fixes

- from this version on macOS 12 Monterey is needed at least to run MoleculeSketch. Older macOS version are no longer supported. - SVG export functionality added. Accuracy of exportet svg image may vary depending on the app used to view the exported svg file. - with macOS 14 Sonoma or newer: new template gallery with more templates (amino acids, carbohydrates, nucleotides) - clipping of stereo bonds reduced - several bug fixes

- spacing between the lines of a double bond can now be changed while editing bonds or in preferences - selection frame now scales with zoom - several bug fixes

- mass calculation works with deuterium and tritium - improved representation of joined stereo bonds - minor bug fixes

- a problem when adding text fields with multiple MoleculeSketch open documents has been resolved - when flipping horizontally or vertically, double and arrow bonds are now adjusted correctly - minor bug fixes

! from this version on macOS 12 Sierra will not be supported any more. To run MoleculeSketch macOS 13 High Sierra is needed at least ! - export your structures and drawings now as eps files (encapsulated postscript) - oxidation numbers can now be displayed automatically. Oxidation numbers are added as textfields and can be moved, formated and changed freely - when changing the charge of an atom the number of free valences when showing hydrogene atoms should now be calculated correctly - a problem that caused the app to use too much memory has been solved - several bugs have been eliminated

- using the arrow keys to precisely position objects is working again - several bugs have been eliminated

- french translation has been added to MoleculeSketch - saving problem in macOS 10.13 High Sierra addressed - stereochemical bonds improved - drawing should be a bit more fluid - other improvements

- SDF files can now be directly imported. Import of V2000 and V3000 mol files is now better supported. - the algorithm to calculate free electron pairs and free valences has been should now take hypervaleces into account. This may cause some changes, if you altered your structure to overcome wrong display of free electron pairs. - bonds should not cross free electron pairs anymore. - arrow-bonds should not be clipped anymore. - under the hood improvements.

- The possibilty to export only selected parts as png, jpeg or pdf file has been restored - Under the hood improvements

- MoleculeSketch now runs natively on Apple silicon chips - One-letter elements (like C, O, N, R, etc.) can now be easily changed in the toolbar by simply typing the letter on the keyboard - Object alignement improved - other small improvements

- functional groups that start with a C-atom will not be affected when changing the visibility of CH-groups - free electron pairs now displayed correctly - other improvements

- the problem that prevented MoleculeSketch to open files in macOS Mojave (10.14) has been resolved - bugs that could occure during migration have been solved - some bonds may not have been copied, but will be now