Huge thanks DStillman. I somehow missed that. It is very bad news. But it is at least good to know where one stands. Sadly not a surprise, but this corporate behaviour is toxic. The value of what Zotero does becomes even more clear!

I will try what you suggest: experimenting with RIS and BibTex exports. But I suspect that if this workaround were good, you would know about it? Otherwise, I need to gauge a strategy that is as robust as possible in the medium term.

Otherwise, since full text file searching is essential for me, it looks from what you say like the best of a bunch of bad bets, is to continue to use Mendeley Desktop locally pending a move to Zotero if and when a more favourable situation arises?

With apologies for this further query, then: does this thinking make sense to you? Are there possibilities that more favourable developments may occur? Or might this instead expose me to likelihood of even worse circumstances developing?

Your advice on these issues is invaluable. I greatly appreciate it.

Thanks DStillman,

It is fantastic to be getting this help. I made a few trials of BibTex export from Mendeley Desktop on single items and the file path transferred fine.

Encouraged by this, I exported all 135,211 items in three roughly equal groups by right-click selecting items in 'all documents' view ordered by 'date added'.

File paths seem to have transferred well overall. But an initial review of results shows other apparent problems. I'm sorry that these complicate this query trail.

First, the number of items successfully transferred in each group was massively smaller than the number of items selected. A total of only 8,500 transferred.

Second, it appears that contents of the 'tags' field have not transferred correctly. Zotero 'display all tags in library' shows very large amounts of extraneous text have imported into this field, including some but not all the tags that should be there.

I'm sorry if I've done anything wrong or misunderstand something. How can I sort the low number of items transferred and the mangling of tag contents?

Huge thanks again and all the very best
Andy

Thanks DStillman,

Again: this help is hugely appreciated – especially so speedy and clear.

I’ll try this. And I also wonder if the sheer volume of export batches may be implicated in the problem? Even if only a small chance, a relatively graspable option for someone with my own limits, might be to export in smaller increments?

Otherwise, I’ll look at the BibTex files. But I fear as technicality rises, so risks grow of me mangling details of diagnoses or actions. As this approaches edges of my competence, a Plan B might be to pay someone trusted and more skilled.

For future reference just in case, would you have any recommendations DStillman, about the general idea or specific suggestions?

Huge thanks again for the fantastic assistance.

All best
Andy

Many thanks again DStillman, for your hugely appreciated support. I've returned to the desk today to battle away with this further.

I fully understand you can't speak for Mendeley, but a first consideration on close examination, is an apparent anomaly that may relate to this problem.

The (in all respects standard) Mendeley Desktop folder I am trying to expert from registers in Windows Explorer with a contents of 63.7 GB. But the displayed sqlite files directly rooted in this total less than 1 GB. Other included folders add virtually nothing, aside from the cache folder (but this is still only 16.9 GB).

So, in a way that strikes my amateur brain on these matters as being odd, there appears to be a large amount of extraneous data here. I wonder if this may be related to the problem I am experiencing with the export?

I realise this is totally Mendeley and not a Zotero problem. But it is why I am trying to migrate and vital to me becoming a Zotero user. Both the embodied work and future utility of this database make the stakes very high for me. So I wonder if you might have any further guidance about what I might do (eg: delete cache folder?) to diagnose whether - or at least reduce risks that - this may relate to the possible malformed entries difficulty that you so helpfully pointed to.

Yours
Andy

Thanks Damnation. Good assumption! I understand what you say and why.

But this is definitely not the attachments directly, since the text file database is located elsewhere and anyhow (as mentioned in above stream) is 700 GB in size.

I wonder if this is some kind of residue of an index file? Maybe irrelevant? My main query is whether this might be implicated in the show-stopping block on migration?

Thanks again for your interest
Andy