Image attachments not working

[NotWiggo]

Can't add attachments from a phone. This is odd, because it works fine on the PC using the GoMobile theme, but when I do it from my phone and select a file, then click on Add Attachment I get the following error message:

"Please correct the following errors before continuing:"

Except it doesn't list any errors, and doesn't add the attachment. Same behaviour using the default Android browser and Chrome, but it's fine from my tablet (Android). Very occasionally my phone shows me a MyBB error page that says that I have exceeded the php post_max_size limit, but I am working with far smaller files than I can add from the tablet.

[Phumix]

Could you test the latest commit? I don't really have an Android phone at the moment that works so I can't test it.

[NotWiggo]

Same issue:

[Phumix]

Have you tested it on any other theme such as default theme?

[NotWiggo]

Works fine from other themes...

[NotWiggo]

This comes up from time to time...
https://www.dropbox.com/s/v6p9gu45opma3f4/Screenshot_2016-08-11-19-29-16.png?dl=0