Beta Testing Open for v6.4

Dear all,

We are busy making preparations for the release of version 6.4 of Mantid. We have completed our first round of developer testing and are now ready for beta-testing feedback. The beta testing period for this release is between today (Tuesday 17th May) and the end of play on Tuesday 7th June. We then hope to release the following week.


Note that the name of the downloaded Mac/Windows packages has changed to MantidWorkbench-versionnumber. This is intentional. The packages still install in the same manner as before.

The nightly test installers for this version are here to download: Please go to the Nightly build Section on the right at the bottom. The nightly builds install alongside a full release and so will not affect its operation but will overwrite any other nightly builds you have. We have made some changes to host the packages in a different place to speed up the downloads.

For Windows users at ISIS, install Mantid as your standard user account (not an 03 account). It will install just for your user, rather than for the whole PC.

Known Issues

We are aware of a few issues with the current build that we would like to highlight but they are not significant enough to hold up beta testing. They will be addressed for the release:

  • Windows installer package is larger than before. We are working to remedy this
  • The in-built documentation is missing screenshots of the algorithm interfaces
  • Double-clicking a plot axes to change it to log gives an error message. Using the settings (cog) button still works
  • We have updated matplotlib to v3.5 and this has produced some additional warnings around deprecation. We have squashed most but some may remain. Please do report them.

We have an early draft of the release notes at Mantid 6.4.0 Release Notes. Please report any bugs to and if the problem is a bug that would prevent your normal workflow from working then start the email subject with URGENT:. It would be most helpful for the team if bugs are communicated back to us as soon as possible.

Thank you all for your help.


Mantid Team