Please test in safe mode, Menu/Help/Restart in Safe Mode

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Hello!
Excuse me for late answer.
Tested in safe mode, with release 24.2.2: still very slow and unusable.
The files I am working with contain personal financial information: cannot share them.
I have tried with  very simple file, containing monthly bank records (just 143 lines) and it is fast even in normal mode.

Created attachment 193784 [details]
File very slow to open and operate on

I have obfuscated the file by changing all letters to "a".

It is not slow for me working with it, a bit slow to load.

Perhaps because there are rows with yellow background for the whole row.
Test deleting that format, select them and apply background color with no fill.

Or maybe the issue is with the link to the external file, you can try with Menu/Edit/Link to external files — Break the link.

BTW, doesn't look a good idea to keep working with XLS files, even for MS it is an unmaintained format.

Working with LibreOffice the better is work with ods, new MS versions are able to open it, or only if you need to share it to people without LibreOffice, use the XLSX format.

I tested attachment 193784 [details] on Windows (different OS and Hardware than comment 0) with several versions of LO Calc, starting from LO 7.3 up to a recent (but not the very latest) 24.8 alpha.

With each newer version, it takes longer and longer time to open the file.

STR (with each LO version):

1. Open attachment 193784 [details]. Take note of the time it takes to open.
2. Save as a new name_version (with the same xls file type).
3. Close the original file.
4. Open the newly created file. Take note of the time it takes to open.
5. Select all worksheets.
6. Select all cells.
7. Clear Direct Formatting (on Windows, [CTRL]+[M], or use the icon on the toolbar).
7.1. (Optional) Unselect worksheets.
8. Save and close the file.

9. Open the file saved in step 8. Note that now the time to open the file is much shorter than in step 4, whichever version of LO Calc is being used.


I have also tested other properties in the original file (e.g. un-splitting each worksheet), but deleting the direct formatting has the most impact (of the properties I tested).


Conclusions:

* Newer versions are taking more time than older versions of Calc on the same xls file.

* Something in the direct formatting is causing some delay on this XLS file. Whether there is some formatting attribute that was not supported before, IDK.

Note:
* I have not tested saving with other file formats.

* In recent days, there have been some new commits aimed at improving XLS performance. This procedure might need to be re-tested in a few days (or weeks) with a newer LO 24.8 alpha in order to see whether the original delays are still reproduced.

(In reply to m_a_riosv from comment #6)

> Perhaps because there are rows with yellow background for the whole row.

Setting attributes (or references) to _whole_ rows or columns has been present in several performance-related reports.

While users could try to reduce the problems by selecting only the relevant area instead of entire rows/columns, LO Calc should try to improve the performance in these cases anyway, considering that selecting entire rows/columns to perform some action is a very frequent procedure by common users (and UX-wise, they are not wrong).

(In reply to m_a_riosv from comment #6)
> It is not slow for me working with it, a bit slow to load.
> 
> Perhaps because there are rows with yellow background for the whole row.
> Test deleting that format, select them and apply background color with no
> fill.
> 

Did it, all over the file. No improvement.

> Or maybe the issue is with the link to the external file, you can try with
> Menu/Edit/Link to external files — Break the link.

Did it. No improvement.
But I think there is a bug. After I broke the (only) external link, the "Menu/Edit/Link to external files — Break the link." menu element is gray, meaning, I suppose, that there are no more external links. Yet, when I open the file, is asks me whether I want to allow updating the external links!
I am attaching the .xls as it is after breaking external links.

> 
> BTW, doesn't look a good idea to keep working with XLS files, even for MS it
> is an unmaintained format.
> 
> Working with LibreOffice the better is work with ods, new MS versions are
> able to open it, or only if you need to share it to people without
> LibreOffice, use the XLSX format.

Thank you very much for the suggestion: I am more than happy to get rid of .xls!!

Created attachment 193788 [details]
Thw example file with yellow background removed and external link broke

Created attachment 193789 [details]
The last sample file, cleaned of data and format beyond the last in every sheet.

The last sample file, cleaned of data and format beyond the last in every sheet. Load quick, a couple of seconds.

There are sheets with cell borders up to the last row and last column, and cell backgrounds.

Maybe the issue is as LO has more columns than xls and the format of the last xls column is applied to the rest of columns automatically.

Hi @Ady, I remember this matter was discussed somewhere, perhaps in another bug.

Version: 24.2.2.2 (X86_64) / LibreOffice Community
Build ID: d56cc158d8a96260b836f100ef4b4ef25d6f1a01
CPU threads: 16; OS: Windows 10.0 Build 22631; UI render: Skia/Raster; VCL: win
Locale: es-ES (es_ES); UI: en-US
Calc: CL threaded