Export not working when a "+" sign is in a diagram element label

[SoloWingX]

Hi. I am trying to make diagrams for my project, which I would like to export into PNG format. I am, e.g., trying to make the diagram for inverse beta decay, which has a positron (e^+) in it. When I export to PNG, Windows Photos cannot open the file saying "It looks like we don't support this file format". When I change the e^+ to e^- or e, it works. Then, experimentally changing the W^- boson to W^+ boson also causes this issue. It seems to be centered around the "+" sign.

[TiDreyer]

Hi, I'm having the same issue. Both PDF and PNG export create a 33 byte text file that's only containing:

exit status 1

A work around is to use e^{+} instead of just e^+.

[willp240]

I also have this problem, the work around of using eg e^{+} doesn't work when you save to png or pdf, the label is just empty.

[Nibbos]

Hi.
I would love to use this with my A-level students but the issue still exists with exporting any labels that require a '+' or '-' symbol (e.g. W+ and W- bosons, electrons and positrons, and any other charged fermion).
I have tried the workarounds suggested, e^{+} and e^+, but neither are successful. The first exports the diagram without the required symbol, the second exports a diagram that won't open (both .png and .pdf formats not recognised).
A fix for this would be really useful, please. I would certainly share and recommend this to students and teachers if this could be rectified.
Many thanks in advance.