When trying to do 'execute if/unless blocks x1 y1 z1 dx dy dz x2 y2 z2 all run say something', everything following 'all' is highlighted red, stating 'Incorrect argument for command at position ... all <--[HERE] '.

There are no issues when attempting to run the command; however, all autocomplete is terminated.

How it looks:

As stated, it does still properly execute, and is only an issue with the display.