Nightmare upgrading to 1.5.8

[inventoryops]

I did finally get my site to work, but I thought I'd post to get any tips/suggestions for next time because this was soooo aggravating. I spent the entire thanksgiving weekend on this and several days the following week.
My site https://inventorybooks.com/ was on 1.5.7 and seemed to be working fine when I decided I wanted to change my PayPal account from Payments Pro to
Standard. When I went to the Payment Modules in setup, it only showed a couple of modules (I think it was just showing the 2 authorize.net modules). My site has been on Zen Cart for 20 years, and even though I couldn't access the payment modules, they were working.
I decided rather than spending time figuring out what was wrong, I would just upgrade to 1.5.8 and see if the payment modules showed up there.
I'm not saying I'm an old pro, but I have been on zen cart for 20 yrs and have done many upgrades during that time without any problems. I also have sites using Joomla and Mediawiki, so I've done this stuff before. My site was pretty basic, just using modules that came with zen cart. the only mods I had was to text and logos for emails and the site.
My normal upgrade flow was to download all files from my site, download the upgade file. Copy the upgrade files over the existing files on my PC, make necessary changes, then upload back to my site and run zc_install. I did that, and the site wouldn' load (it opened the page pointing to errors in configure.php files). The configure.php files were fine as far as I could tell, but it kept giving me those errors.
I then started trying every Idea I could think of to get it to work, including installing a clean version in another directory on the site, then copying that to the main site, and even installing on another site I had (on the same hosting account Siteground). I even switched from uploading a zip file to the server and extracting it there (how I have done it in the past), to manually uploading groups of files . There was always something that didn't work, everything from the template not loading, to the all producst page not working, to papal not working. the clean install I did on the other site was the closest to working, so I moved that to my main site, and, of course, more stuff didn't work. I was ready to throw in the towel, so I restored my 1.5.7 site from a backup and was prepared to just give up. But giving up was not really part of my dna, so I tried one more time to do a clean install in another directory on my main site, then started making the changes to get it to be my main site.
That worked... mostly. The payment modules were back and I was able to downgrade to paypal standard. But in some browsers it looked like the template didn't load if i cleared the cache. Also, I used to have quantity discounts that worked, and they no longer did. My zen cart site did a fair amount of transactions 20 years ago, but it doesn't any more, so this was good enough for me.
So even though I got it working (for the most part) I don't know what was wrong before or what went wrong with the upgrades. So I'm just looking for any input on options to look at in the future.

[lat9]

TL;DR ... Could you re-post with some spacing between paragraphs?

[dbltoe]

Here's a split with my comments

I did finally get my site to work, but I thought I'd post to get any tips/suggestions for next time because this was soooo aggravating. I spent the entire thanksgiving weekend on this and several days the following week.

Did you look at all the upgrade options in the docs? Including those for Database-Only Upgrade Instructioons? With today's rapidly changing PHP and so many upgrades to ZC between even 1.5.7d and 1.5.8, I never consider anything else.

My site https://inventorybooks.com/ was on 1.5.7 and seemed to be working fine when I decided I wanted to change my PayPal account from Payments Pro to
Standard. When I went to the Payment Modules in setup, it only showed a couple of modules (I think it was just showing the 2 authorize.net modules). My site has been on Zen Cart for 20 years, and even though I couldn't access the payment modules, they were working.

Why are you not using PayPalExpress? Much more stable.

I decided rather than spending time figuring out what was wrong, I would just upgrade to 1.5.8 and see if the payment modules showed up there.

They do show up each time and you are less likely to miss a file when doing the Databast-Only Upgrade.

I'm not saying I'm an old pro, but I have been on zen cart for 20 yrs and have done many upgrades during that time without any problems. I also have sites using Joomla and Mediawiki, so I've done this stuff before. My site was pretty basic, just using modules that came with zen cart. the only mods I had was to text and logos for emails and the site.

With you on the old pro (since 2004) but, there were maybe less changes from 1.5.1 to 1.56c than there was from 1.5.7d to 1.5.8a. The move to 2.0.0 will be even greater. Also, with the PHP versions going End Of Life (EOL) every three or four months, very few mods could withstand the drop of all but PHP 7.4 and it's been "dead for over a year. Since the goal is to sell product, taking the time to make everything you had going work with the new version uses up valuable time.

My normal upgrade flow was to download all files from my site, download the upgade file. Copy the upgrade files over the existing files on my PC, make necessary changes, then upload back to my site and run zc_install. I did that, and the site wouldn' load (it opened the page pointing to errors in configure.php files). The configure.php files were fine as far as I could tell, but it kept giving me those errors.

If this is any of the upgrade suggestions, it should not be. You were in the "Murphy was an optimist" area in trying to upgrade in that manner. Unfortunately, you were pretty much doomed from the start.

I then started trying every Idea I could think of to get it to work, including installing a clean version in another directory on the site, then copying that to the main site, and even installing on another site I had (on the same hosting account Siteground). I even switched from uploading a zip file to the server and extracting it there (how I have done it in the past), to manually uploading groups of files . There was always something that didn't work, everything from the template not loading, to the all producst page not working, to papal not working. the clean install I did on the other site was the closest to working, so I moved that to my main site, and, of course, more stuff didn't work. I was ready to throw in the towel, so I restored my 1.5.7 site from a backup and was prepared to just give up. But giving up was not really part of my dna, so I tried one more time to do a clean install in another directory on my main site, then started making the changes to get it to be my main site.

Now we're talking!

That worked... mostly. The payment modules were back and I was able to downgrade to paypal standard. But in some browsers it looked like the template didn't load if i cleared the cache. Also, I used to have quantity discounts that worked, and they no longer did. My zen cart site did a fair amount of transactions 20 years ago, but it doesn't any more, so this was good enough for me.

You still need to consider using only Express. As you found with Quantity Discounts, not every contributor is able to keep up with coding changes AND, sometimes the mod is incorporated into the core.

So even though I got it working (for the most part) I don't know what was wrong before or what went wrong with the upgrades. So I'm just looking for any input on options to look at in the future.

Here's my steps when doing any upgrade:

1. If possible, keep the current site running an create a test site to upgrade
2. Load the lastest version from https://github.com/zencart/zencart/releases - NEVER use any other source
3. Go to Plugins Manager and turn on Display Logs - You'll want to know any bumps in the road as soon as possible.
4. Load Mod List and Clone a Template - both go into the zc_plugins directory and will load easily and correctly.
5. Regardless if you are going to use it, Clone responsive_classic to resp_your-site before making any changes.
6. Load the bootstrap template
7. Go to layout boxes controller (Tools in the Admin) and copy the layout from responsive_classsic to bootstrap.
8. Change the template to bootstrap and clone it to boot_your-site.
9. You now have two template options and a fallback/testing location if something goes wrong with customization.
10. Replace your new database's contents with the contents of the old database.
11. Run zc_install to upgrade the database.
12. Use Mod List (Admin > Tools to let it tell you what may need to be culled out of the database from the old site. NOTE: If it takes a while to get the test online, you may have to do 10 - 12 over again to get all the data added to the old DB while setting up the new site.
13. If you use One Page Checkout (OPC) and decide to load it, do not load it's sideboxes folder. It doesn't play well with bootstrap. It's in the docs but few bust through the shrink wrap.
14. Set up PayPal Express. It's the most reliable of the bunch
15. Set up some shipping module that will work with your site.
16. Decide which template you want to use and select it.
17. Make sure any define pages you had on the old site are brought over to the test
18. You now have a site that, while not perfect, can sell, collect monies, and ship.