Hello @Volkmar
I hope you are doing well, and thanks for reaching out. We're sorry for the trouble you had.
Could you please share more details about the issue?
Are they using the web-based Acrobat PDF compressor (in a browser) or the desktop Acrobat app? (A) Web, (B) Desktop
After downloading the compressed file, are they still on the same webpage/tab, or did they navigate away/close it?
Are you on a Mac or Windows machine, and what is the version?
Can you please share a screenshot of the window you get where the upload option is not available?
Open the Adobe Acrobat online PDF compressor page:
https://adobe.ly/4fr17EC
Click Select a file, or drag and drop the next PDF into the drop zone. Adobe’s online compressor page documents this as the upload step for a PDF file.
Select the PDF you want to compress.
Choose the compression level if prompted, then let Acrobat compress the file. Adobe documents High, Medium, and Low compression levels for the online tool.
Click Download to save the compressed PDF, or sign in if you want to share/save it through Acrobat online services.
Alternatively, if you are already signed in to Acrobat on the web:
Go to Acrobat on the web: https://adobe.ly/4fw3RAR
From the Acrobat on the web homepage, choose Convert > Compress a PDF.
In the file dialogue, choose the file location, select your PDF, and select Continue.
Select the compression level, then select Compress.
After compression, use the download option shown in the notification.
For more details, you can refer to this article: https://adobe.ly/4fpGg4K
Please note that if you don't sign in to Acrobat web or Acrobat browser extensions with an Adobe ID, you can only complete one free transaction and download the resulting file one time. There are also a few tools that you can’t try without signing in. Check this article for more details: https://adobe.ly/4ysZRK1
Let us know how it goes, and please reach out if you need any assistance.
Regards,
Anand Sri.