Today spatstat 1.64-2 ‘NICKNAME’ has been uploaded to CRAN where Windows and OSX binaries are also available. You can also download it from the github repository. The main changes are (full release notes here):

• spatstat now depends on the new package ‘spatstat.sparse’.
• spatstat now depends on R version 3.5.0 or later.
• Changed default value of ‘stringsAsFactors’.
• predict.mppm now works for multitype point process models.
• Improved handling of ‘newdata’ in predict.mppm.
• More support for multi-dimensional patterns.
• Bug fixes and minor improvements.