Created attachment 203215 [details] Sample ODP The attached ODP contains a comment with the following text: < > & " ' These are special characters in XML, and should be written escaped. However, when the ODP is saved as PPTX, and is unzipped, it can be seen that ppt/comments/comment1.xml includes them as is. PowerPoint is unable to open such a file. Observed with LO 26.2.0.0.alpha0+ (8ea8e254a3151f5390f3a10ff156fcaf8e7c5d5c), 4.0.0.3 / Windows. Also affects: kde239476-1.ppt, kde239476-9.ppt.
Aron Budea committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/core/commit/6cab4cb50cf67a8dd595fffa107968cb1bd9fd18 tdf#168754 sd: escape comments exported to PPTX It will be available in 26.2.0. The patch should be included in the daily builds available at https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: https://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.