Writer 6 cannot open ODT document created in Writer 5

Hi,
I created ODT two years ago in Writer 5. I have updated Libre Office continually and I edited document last year.
Nowadays I use Libre Office 6. I have tried to open this document but I cannot. Writer freezes immediately after it starts and hangs out for such long time so I never wait while it open.
Is there some process to make Writer 6 open this document?

Thanks in advance.

Can you show us your problem file?

Yes I can. Tell me how can I upload file here.
I found wrong paragraph. I don’t know what is wrong with it but when I remove it (in Writer 5) then I can open it in Writer 6.

May I share link. Here it is ODT

it is a bug. please fill bugreport on bugzilla - bugs.documentfoundation.org and attach your file

Source: [Solved] Writer crashes while opening specific document (View topic) • Apache OpenOffice Community Forum

Upload to zamzar or similar website and let it convert into doc or rtf or pdf. Then open it again and save as odt document.

Other workaround: Rename your odt file into zip and then unzip it. The CONTENT.XML contains all text, but after extracting you have to entirely format again.

It’s worth a try…

Thank you for your advice. I can try it but formatting is most difficult part of the document. :frowning: