On 6 May 2020, at 1:26, Tim Bates wrote:

More weirdness (in addition to page blanking multiple time s day)... files appear empty (empty window, line 1 only, no characters...).

This is a hunch, but try delete ~/Library/Caches/com.macromates.TextMate/BundlesIndex.binary.

If you use import filters, and the index points to a non-existing (enabler) filter, I think it would effectively fail to open (process) the file, but not handle that gracefully.

The handling of corrupt bundle index is definitely something that needs improving.