>>"Some of my blocks with masking and some XRef lines would not change.
Not change, does mean exactly? What step/command will not change What inside this block?
 
>>"Some of my blocks with masking and some XRef lines would not change.
Your Xref-content is part of another file, your commands don't change another file than the current one.
>>Guess I would haver to convert all the XRefs also.
If you have to send these files too, or if you want to plot from your .stb-DWG, Yes.
 
 
>>"In one file with MTexts, like the texts have white backgrounds."
Without the cad-data (.dwg with your Text/MText with background), hard to say. And I can't read about an issue!?
 
>>Just Curious, for now, is there a way I can just manually convert all my drawings files to be able to use the client's STB?
We spend a lot of our time (and also the people who not posted, but worked on) and offered all information, and you ask this Question???
All what we explained is what you have to do to use the client.stb
 
I probably have a translation problem, as I don't understand this question at all at this point (2 months after the thread started).
I'm sorry if that's the case.
 
>> I mean, open the drawing, and change all layers (manually) to use the client's STB,
>>than using the CONVERTCTB
For what?
If client.stb contains a color table, use client.stb
If not, you should already created a "color ctb to stb.stb" or similar!?
how to: Run ConvertCTB, select the original ACAD.CTB, saveas FromCTB2STB.stb, Edit the FromCTB2STB.stb content (rename Style1 to Color)
 
 
>> and CONVERTPSTYLES
yes, with your FromCTBtoSTB.stb
 
 
And all the other steps you need
 
Please excuse me too, but I am a little frustrated 😐