Thanks for letting me know. I'll try to reproduce it.

Textastic can open and highlight .tex files just fine.

How are you trying to open the file? In case you are trying to open it using the Open… command and Google Drive:

This is a problem when opening files from Google Drive using the "Open…" command in Textastic. This invokes the iOS document picker and uses the Google Drive file provider extension of the Google Drive app. Unfortunately, the Google Drive app has some bugs.  

Instead, please use the remote transfer screen of Textastic: tap on the "globe" button in Textastic and create a new Google Drive connection. You can then download and upload files using this connection. It also allows you to download whole directory trees.  

It's basically the same functionality as for Dropbox, which is explained here:  
https://www.textasticapp.com/v6/manual/lessons/How_do_I_access_files_in_my_Dropbox_account.html

Can you please send me an example file that crashes the app when using that bundle?

Thanks! I'll think about it.

I already have this implemented in the Mac version of Textastic and I do plan to add it to iOS eventually. I'm just not sure about the UI - i.e. were to put a button to invoke it in addition to a keyboard shortcut. Suggestions are welcome! :)

Hello,

this is a problem when opening files from Google Drive using the "Open…" command in Textastic. This invokes the iOS document picker and uses the Google Drive file provider extension of the Google Drive app. Unfortunately, the Google Drive app has some bugs.

Instead, please use the remote transfer screen of Textastic: tap on the "globe" button in Textastic and create a new Google Drive connection. You can then download and upload files using this connection. It also allows you to download whole directory trees.

It's basically the same functionality as for Dropbox, which is explained here:
https://www.textasticapp.com/v6/manual/lessons/How_do_I_access_files_in_my_Dropbox_account.html

Yes, exactly. Textastic 6.3.1 uses the latest version of libssh2 which supports more ciphers.

I don't think you can disable it when click on the Dock icon. Yes, with Cmd-Tab it works.

You can change that behavior, too: if you want that Textastic opens a new untitled file instead of the open dialog, you can use this command:

defaults write com.textasticapp.textastic-mac NSShowAppCentricOpenPanelInsteadOfUntitledFile -bool false