I managed to fix the problem. I am reporting because this may be an occasional bug.

WHAT I DID

Following search-engine AI-advice to the search term "gretl fix a corrupted session file", 

1. I copied the session file that would not open, 

2. Changed its extension into ".zip", 

3. Unpacked and turned the "pwt110.gdt" file that was in there among other files into a ".txt" file

4. Opened it and inspected, and found some weird "labels" in a few variables as follows

5. Deleting these labels (not the variables), and then reversing the previous steps allowed gretl to open the session ok.

Now these specific variables are created inside a loop,

...

loop i=1..74
    
    smpl year == 1949+i --restrict
    smpl --no-missing rgdpna rnna emp
    smpl d_IMF_DE==0 --restrict
    MLEestToW_EMDE[i,1]=1949+i
    MLEestToW_EMDE[i,2] = $nobs
    
    series l_rgdpna = log(rgdpna)
    series l_rnna = log(rnna)
    series l_emp = log(emp)
    
series Depvar = l_rgdpna

...

It is not the first time that I noticed that gibberish labels like these appear, when the variables are created inside a loop. So maybe there is something here for the developers.


Alecos Papadopoulos PhD
Affiliate Researcher
Dpt of Economics, Athens University of Economics and Business
web: alecospapadopoulos.wordpress.com/
ORCID:0000-0003-2441-4550


-------- Forwarded Message --------
Subject: [Gretl-users] Problem with opening existing gretl session
Date: Sat, 4 Jul 2026 18:18:35 +0300
From: Alecos Papadopoulos <papadopalex@aueb.gr>
Reply-To: Gretl list <gretl-users@gretlml.univpm.it>
To: Gretl list <gretl-users@gretlml.univpm.it>


I run Windows 10 gretl release 2026b.

I get the following when I try to open an existing gretl session. I have closed and opened it in the past, no problem. 

I looked at the path, after "...\Roaming\gretl\",  there does not appear to exist "...\.PWT_110_2TSF" at all so neither "...\.PWT_110_2TSF\pwt110.gdt".

It has happened also in the past with other sessions. Any advice as to what I could do to fix this?

Thanks.

-- 
Alecos Papadopoulos PhD
Affiliate Researcher
Dpt of Economics, Athens University of Economics and Business
web: alecospapadopoulos.wordpress.com/
ORCID:0000-0003-2441-4550