Known Issues
MEGA is not optimized to run on Apple's new M1 processors

MEGA currently does not support newer macOS computers that have ARM-based M1 chips. Although MEGA has been run on these computers, performance is sluggish and for large data, MEGA may become unresponsive. We are currently developing a version of MEGA that will run natively on macOS system with the ARM-based architecture. In the meantime, macOS users can download the Windows or Linux version of MEGA and run it using virtualization software such as VMWare Fusion, Parallels, or Crossover.

My Tree Explorer window has a floating blue box that I can't get rid of

Some users have experienced an issue where a blue rectangular box appears in the Tree Explorer window. To get rid of the box one can restore MEGA to its default settings by deleting MEGA's saved settings files:

  1. Close MEGA if it is open. In a file system explorer window navigate to the folder where MEGA keeps its settings files and delete the folder that contains the settings files:
    • On Windows: open a File Explorer window and type %localappdata% in the address bar and press enter button on your keyboard. Navigate to your MEGA\MEGA_buildnumber\Private folder and delete the Ini folder that is there.
    • On Linux: navigate to your ~/.config/MEGA/MEGA_buildnumber/Private directory and delete the Ini directory
    • On macOS
      • For MEGA12 and later, right-click MEGA in your Applications folder and select Show Package Contents. Navigate to Contents/Resources/Private and delete the Ini folder
      • For MEGA11 and earlier, navigate to your ~/.config/MEGA/MEGA_buildnumber/Private folder and delete the Ini folder
In the above, the actual path to your Ini directory will depend on the version of MEGA you are using. The path will look something like %localappdata%\MEGA11\MEGA_11220624-x86_64\Private\Ini or ~/.config/MEGA11/MEGA11_11220624-x86_64/Private/Ini

NCBI BLAST is no longer working in MEGA7 and earlier

Recent updates to the NCBI BLAST web page are not compatible with the integrated web browser used in MEGA7, MEGA6, and MEGA5. Because these versions are no longer actively developed the issue will not be fixed. The workaround is to either install MEGA X or use NCBI BLAST from your own browser (e.g. Chrome, Firefox, Edge, Windows Explorer, Safari, etc...). When using BLAST from your own browser, you can download the results in the FASTA format and then open the downloaded file in MEGA's Alignment Explorer.

Font styles may not be preserved in exported PDF files

The PDF export option in MEGA's Tree Explorer is a work in progress and is not feature complete. Consequently, italic and bold font styles are not preserved when exporting trees to PDF files.

MEGA7 will not run on macOS 10.15 (Catalina) and later

As of macOS version 10.15 (Catalina), Apple has dropped support for 32-bit applications entirely. To run MEGA7 on Catalina and later versions of macOS, the Windows version of MEGA7 can be used if it is ran using virtualization software such as VMWareFusion. MEGAX will run on Catalina and later starting in version 10.1.4.

Tree Explorer may not map mouse clicks correctly when DPI scaling is used

Microsoft Windows has a setting to "Change the size of text or other items on your screen" which when not set to the default value (100%) breaks the mapping of mouse clicks in the Tree Explorer window. The workaround is to set this option to the default value.

Integrated help system has problems for the Mac version

When utilizing the integrated help for the Mac version of MEGA, the Index and Search tabs may be inoperable. The workaround is to use the online help manual .

PDF images are sometimes cropped

Some users have experienced a problem where saving tree images to a pdf file results in a cropped image. This is a mysterious bug that we have never been able to reproduce. There are a couple workarounds:

  1. Save the image as a png or emf file.
  2. Copy the image to the system clipboard and paste the image into GIMP, Photoshop, or other image editing application. Then save the file in the desired format.

GIMP might complain that there is no data on the clipboard. If so, first paste the image into a Word file, copy it from the Word file and then paste into GIMP.

Starting in MEGA 6, older tree session files cannot be opened and alignment session files lose some information

A much needed design change in MEGA's session file system has made it necessary in MEGA 6 to disallow opening of tree session files that were generated using previous version of MEGA. A workaround is to open an older session file using the version that was used to generate it (older versions can be downloaded here), export the tree to a .nwk file, then open the .nwk file in MEGA 6. A new session can then be saved.

Additionally, when opening alignment session files that were created with previous versions of MEGA, some information is lost. The sequence data will be retrieved but the settings used for alignment as well as the form state (font, colors, etc...) will be lost.

Tree session files (.MTS) generated with MEGA 5.05 and earlier have trouble being viewed in MEGA 5.1 and MEGA 5.2

If you have files generated with MEGA 5.05 or earlier, they are best viewed in MEGA 5.05. You may download MEGA 5.05 here .

MEGA for Mac Stability

Most Mac users have reported positive experiences when using MEGA (using the Wineskin wrapper and installer that we provide). However, we also have recieved feedback from some Mac users that have experienced stability issues.

If you are one of the Mac users who experiences problems with the wrapper that we provide, there are alternative options for running MEGA on a Mac system. For instance, MEGA can be run using virtualization or emulation software. Many options for doing so are available including Parallels (commercial), Crossover (commercial), VMWareFusion (commercial) or VirtualBox (free)

MEGA Compatiblity with WINE (Wine Is Not an Emulator) Project

Several users have written into us saying that MEGA runs ok under WINE on Linux systems. We do not offer support for users running MEGA on WINE, and can not offer assistance on installing or configuring WINE.