MS Office documents do not open in MS Office Mobile apps

I can't find this issue anywhere in the forum, but maybe someone can help me?

I have Dopus on my Windows 10 tablet, which comes with Microsoft's Mobile version of Microsoft Office.
If I double-click an MS Word or Excel file from Windows File Explorer they open ok in the relevant Mobile app.
But if double click the file from Dopus it opens in the Dopus Hex viewer.

Does anyone know why Dopus isn't picking up the associated application for .xlsx and .docx file extension? It does display the correct icons for these file extensions, so it must know they are MS Office files. But it seems to be unaware of the MSOffice mobile edition and gives up if it can't find a full MS Office edition to run. I can't find anything in Dopus preferences to force it to work properly.


That should work in newer versions of Opus. Opus 10 dates back to before Windows 10 existed, and we needed to make some changes over the years to support the way Metro / Universal apps register themselves against filetypes with the rest of the OS.

If you try the Opus 12 free trial you can check if it is working (and if it isn't please let us know as it definitely should work in current versions).

Many thanks for that rapid reply.
I don't particularly need all the new features in Dopus 11, so I can't justify the upgrade cost. V10 seems to work ok for me in other respects apart from this one.

I have just found an awkward workaround -right click on the file in Dopus and select Open With ... That pops up "How do you want to open this ... file" and under "Keep using this app" it shows an Office mobile app. Selecting OK then opens the file ok.

There must be a better workaround than this though. Do you have any suggestions? For example, is Dopus perhaps looking for a registry key that isn't there? I am an experienced programmer, so am not adverse to applying patches, if you could give me a clue on what needs patching?

Sounds like this very problem is a good way to justify the upgrade cost :slight_smile:

I know you meant that in a light hearted way, and I don't object to paying for an upgrade if it gives me new features and enhancements that I want to use, and I have in fact bought an upgrade license in the past. But I don't see why I should have to pay to get defects fixed. What I do expect is for GP Software to release maintenance fixes for all versions its customers are still using, not just for the latest v11.

Put another way, if I have to pay to get this v10 issue fixed, then I am left wondering how many more defects will I have to pay for in the future. So if GP software is not going to fix this v10 defect, then I will have to consider if I want to continue using Dopus. I could live without it and use Win10 File Explorer instead -creating Quick Access folders named the same as my old Dopus groups, and putting shortcuts in each folder that correspond to the tabs for the corresponding group. It would take two clicks instead on one to go to a folder, but it's no more effort than Dopus, where I select a tab group then select a tab.

Whether or not I decide to drop Dopus or not will depend on the next comment I see from GP Software in this thread.

Thanks for listening.

It's not a defect in Opus 10, the problem is a result of changes that were introduced in the operating system since Opus 10 was released (and development on Opus 10 ended almost three years ago). Presumably you have upgraded your version of Windows in that time, and I doubt Opus is the only program you've found that you needed to upgrade along with it.

Whether you choose to drop Opus is entirely up to you but look at it from our point of view; if you're definitely not going to upgrade under any circumstances, then why would it bother us if you stop using Opus or not? We run this as a business that sells software. If you're happy with Opus as it is and have no interest in any further developments in the product then that's entirely your choice but you also then have to accept that you're on your own if you decide to change your operating system to one that didn't even exist when your version of Opus was written.

As an experienced programmer you should know, that older software often gets incompatible, esp. with new Windows-versions and that updates are necessary to earn money! As experienced programmer you may earn more money in the same time you need for finding a fix than you would spent for the upgrade (btw. it's not a fix, DO10 simply is not fully compatible anymore). As an experienced programmer you know, that the upgrade- and support-policy of DO is good, but yes, there're lots of other examples I would agree with you (e.g. Acronis TI as "famos" example). As an experienced programmer you also know that no software is free of bugs and the use of the trial is a fair option to test things. Do you also ask MS to fix bugs in Office 2003/2007 combined with Win 10 or Adobe in older suites?

To avoid misunderstandings: I'm not from GP, I'm just a normal customer and simply don't understand the way some people think! Better never buy a smartphone if you want free and long upgrades.

Also bear in mind that 11 isn't the latest... 12 is the latest.

I would agree with you if it was just one of those niggling minor defects, but the ability of any file manager software to open a file in the default application associated with the file's extension, is core functionality.

The Windows API has not changed for opening files in Windows 10. It's the same as in Win7/8. I don't know in which language Dopus is written, but in C# it's just a one-liner, for example: System.Diagnostics.Process.Start(@"C:\Temp\mydoc.docx");

The failure of Dopus 10 to open files using Office mobile apps, suggests it is using non-standard methods for opening files, i.e. this defect has nothing to do with Windows 10 compatibility. I am willing to bet if Microsoft ever releases Mobile Office apps for Win 7/8, Dopus 10 will have the same problem.

You may be right, but mobile apps didn't exists as DO10 was released (2011!) and if you want DO10 workin again, revert back to Win 7 where it was designed for. Again, yes, it's maybe a bug (I'm not a programmer), but you can't expect outdated apps to work years later with newest OS. And how long should DO10 be supported in your opinion?

DO10 also doesn't support lots of other things that came with Win10, what about these? Where to make a cut? Only on things you need? What about others not using mobile apps, but wanted other things to be fixed?

BTW threaten not to use DO anymore when this won't be fixed surely is not the smartest way :wink:.

The way Metro apps register themselves was nonstandard prior to their introduction, and the exact details of the API are not actualy documented, and subject to change at Microsoft's whim.

MS document how to register apps, but not how to be on the other side and find which registered apps are registered.

When they add new rules or break the rules, they change the part of the OS which handles the other side to correspond to the new rules (if needed; it may already work as they wanted, but since it isn't documented, anyone else aiming to do the same may work differently up to the point where the difference matters; differences which don't matter are impossible to detect unless Windows goes open source). Once a difference is addef to the OS and discovered, we then need to make changes to accommodate it.

There is no API for a lot of this stuff, other than a very high level one which we can't use everywhere as we need more granular control, due to allowing the user to reconfigure what happens on doubleclick etc. Apps that need more granular control must go through the registry themselves and collate the data, which is spread all over the place and has new rules and complexities layered on top every couple of Windows versions at least. (This part of Windows is an absolute mess, to be blunt.)

A lot of the Windows shell APIs are designed and documented with the assumption that the shell itself is the only thing that will ever be on its side of the API. (Similarly, IE ActiveX plugins were only ever documented from the plugin side, not the host side, and writing an ActiveX host involves months of testing different components to work out the assumptions they make about how and in which order IE does things, none of which are part of the documented API.)

Keeping things like this working when the OS changes them takes research and ingenuity, which means time and money. We aren't in a position to give that away for free to people two major versions behind and using a version that was never supported on an OS version which didn't exist at the time it was made nor through the multiple years that Opus version remained supported with free updates. We give a lot of updates away for free, both fixes and functionality, but there are limits.

Nor could we, when writing Opus 10 over 5 years ago, predict the future and guess that Windows 10 would add new requirements to that code. It is an ongoing maintenance task each time Windows is updated.

We wish it wasn't, and that there were proper, never-breaking APIs and docs, so we could focus on more interesting work, but it is what it is.

Whether you value that work enough to pay for our time more than once every 5 years is entirely up to you.

That's all very interesting but I think GP software is over-designing its code here. Dopus doesn't need to tell the O/S which application to use to open a file; it just needs to pass the filepath to the O/S and leave it to Windows to sort out what app to open it with. Hence there is no need for it to plough through the registry hives to work it out for itself.

As for the reasonableness of asking customers to pay for development, I made the point earlier that I expect to pay for enhancements such as support for new Windows features, and I have bought licenses for 2 different versions of Dopus already, but I don't expect to have to pay to get major defects fixed in existing functionality such as the ability to open MSOffice documents.

Unfortunately you will need to adjust your expectations. Development on Opus 10 ended with the release of Opus 11; it could be a one line change and the answer would still be the same.

Abandoning customers who are only 1 or 2 versions behind, doesn't sound like a good long-term business plan to me. The company I work for supports clients with fixes going back to whichever version they happen to be using. We think that is reasonable as not all clients are able to upgrade on demand, and it makes for happy customers who do eventually upgrade because they get good support from us.
So I guess that's it for me; goodbye Dopus and hello Explorer++ .

I should add that we are all very much aware of how hard it is to win new clients and how it is all too easy to lose them. In my case, I had a good 11 year run. I may give Dopus another go one day, once I've got over the feeling of being let down. Bye all.

So you're going to switch to something else that's massively cut down instead of ugrade the thing you want to use, because you think we should update a six year old version to support something that didn't exist for the three+ years we gave away free and significant updates, and you want us to do that for free as a long term business plan of working for nothing for people who don't want to pay us?

That has not convinced me to reinstall the old development tools, dig the old source code out of the archives, and spend several hours writing, testing and releasing a special change just for you, as no one else is asking, in the hope that maybe one day in the next decade you might give us £30 to share between the team, I must admit. :slight_smile:

But if E++ (which is donation - attention not to pay too much!) can replace DO, DO never was the right app for you. For the time you spent writing these lines you would have easily earned the money for the upgrade as an experienced programmer. A good-bye really seems best solution for all, so good-bye!

Childish, really.